HUMAN EVOLUTION - UCL



-519551257301UCL Anthropology,??University College London, 14 Taviton Street, WC1H 0BWHUMAN EVOLUTION00UCL Anthropology,??University College London, 14 Taviton Street, WC1H 0BWHUMAN EVOLUTION-530629204360017348201194031UCL AnthroSchools0UCL AnthroSchools-525145000Table of Contents TOC \h \z \t "Heading 1,2,Heading 2,3,Heading 3,4,Title,1" Teacher’s Guide PAGEREF _Toc63285624 \h 3How to Use this Resource Pack PAGEREF _Toc63285625 \h 3Aims of the resource pack PAGEREF _Toc63285626 \h 3Who is this for? PAGEREF _Toc63285627 \h 3What does it address? PAGEREF _Toc63285628 \h 3How do you use it? PAGEREF _Toc63285629 \h 4How are the worksheets structured? PAGEREF _Toc63285630 \h 4Future Resources and Looking Ahead PAGEREF _Toc63285631 \h 51 Genetic Diversity and Adaptations in Humans PAGEREF _Toc63285632 \h 6Worksheet details PAGEREF _Toc63285633 \h 6Sections PAGEREF _Toc63285634 \h 6Suggested Timings PAGEREF _Toc63285635 \h 6Syllabus Points PAGEREF _Toc63285636 \h 61.1 Human adaptations and selection pressures in hominid evolution PAGEREF _Toc63285637 \h 7Learning Outcomes PAGEREF _Toc63285638 \h 7Adaptations in hominids PAGEREF _Toc63285639 \h 7Theories of bipedalism PAGEREF _Toc63285640 \h 81.2 Recognising selection from fossil evidence and data PAGEREF _Toc63285641 \h 9Learning Outcomes PAGEREF _Toc63285642 \h 9Trends in human brain size PAGEREF _Toc63285643 \h 9Selection in human brain size PAGEREF _Toc63285644 \h 101.3 Natural selection in lactose intolerance and adaptive phenotypes PAGEREF _Toc63285645 \h 12Learning Outcomes PAGEREF _Toc63285646 \h 12Evolution of lactose intolerance PAGEREF _Toc63285647 \h 12Genetic Diversity PAGEREF _Toc63285648 \h 131.4 Phenotype and Environment – Sickle cell disease case study PAGEREF _Toc63285649 \h 15Learning Outcomes PAGEREF _Toc63285650 \h 15Sickle Cell Disease and Malaria PAGEREF _Toc63285651 \h 152 Human Evolution: Speciation and Taxonomy PAGEREF _Toc63285652 \h 18Worksheet details PAGEREF _Toc63285653 \h 18Sections PAGEREF _Toc63285654 \h 18Suggested Timings PAGEREF _Toc63285655 \h 18Syllabus Points PAGEREF _Toc63285656 \h 182.1 Processes of evolution PAGEREF _Toc63285657 \h 19Learning Outcomes PAGEREF _Toc63285658 \h 19Speciation PAGEREF _Toc63285659 \h 19What does evolution look like? PAGEREF _Toc63285660 \h 192.2 Classifying Human Species PAGEREF _Toc63285661 \h 21Learning Outcomes PAGEREF _Toc63285662 \h 21Taxonomy and classification PAGEREF _Toc63285663 \h 21Phylogeny PAGEREF _Toc63285664 \h 23Genetic sequencing PAGEREF _Toc63285665 \h 242.3 Extension challenge: Species in the hominin lineage PAGEREF _Toc63285666 \h 25Learning Outcomes PAGEREF _Toc63285667 \h 25Who are the hominins? PAGEREF _Toc63285668 \h 25Early hominins PAGEREF _Toc63285669 \h 26Australopiths PAGEREF _Toc63285670 \h 27The Genus Homo PAGEREF _Toc63285671 \h 28 PAGEREF _Toc63285672 \h 29Timeline of human evolution PAGEREF _Toc63285673 \h 29Extra Resources PAGEREF _Toc63285674 \h 30Glossary PAGEREF _Toc63285675 \h 31Teacher’s GuideHow to Use this Resource Pack?Welcome to this?AnthroSchools?Evolution Resource Pack! Thank you for downloading.???At?AnthroSchools, we are focused on supporting teachers to deliver effective and challenging material by utilising anthropological knowledge to supplement and consolidate learning at A-level.?Anthropologists study humanity in all of its diversity and?similarity, both past and present, and evolution is a core topic for all anthropologists to understand human origins, behaviour?and adaptation. Anthropology seeks to answer big questions about evolution.???We hope that the materials provided here will challenge students to apply their knowledge of human evolution and reinforce their learning in A-level Biology. Contained within this resource pack are a series of worksheets that address core topics on evolution in A-level Biology. In this how-to-use guide, we will provide you with some brief guidance about how to get the most out of the worksheets to apply anthropological knowledge to biology material at A-level.??Aims of the resource packTo start, the aims of the resource pack are:?Consolidate and support classroom-based learning about A-level biology knowledge about evolution.??Challenge students to apply their knowledge to answer complex questions about human evolution.??Develop?students’?critical thinking skills?to think?across different topics?about the relevance of what they learn.??Deepen their understanding of broader evolutionary processes.??Who is this for??This resource pack has been tailored to accompany the AQA A-Level Biology specification to support Key Stage 5 students in their learning about human evolution.??What does it address??The two broad topics included in this pack are:??Genetic Diversity and Adaptations in Humans??Human Evolution- Speciation and Taxonomy??This covers the following points in the AQA A-Level Biology Syllabus?3.4 Genetic Information, variation and relationships between organisms?3.4.4?Genetic Diversity and adaptation?3.4.5 Species and Taxonomy?3.7?Genetics, populations, evolution and ecosystems?3.7.1 Inheritance3.7.2 Populations3.7.3 Evolution may lead to speciation?How do you use it??Each?part?of the resource pack has been designed to address specific topics within the study of human evolution as prescribed by the AQA A-Level Biology specification. Each?worksheet?contains?multiple sections?with varied and challenging questions. The pack has been designed to allow teachers to select specific sections to use as in-class activities?and/or?homework tasks.????While sections build on each other, if you would like to?select?a particular, individual?section to address one specific topic (e.g.?lactose intolerance), you can. Students can either fill out the worksheet?continuously?over a series?of lessons or they can simply focus on a particular topic?and return to the worksheet at another time.????The pack has been designed to give you the most flexibility and challenge your students to think across topics while continuously supporting their learning.??How are the worksheets structured??Students will face a variety of questions in different formats, including short and long answers, fill-in-the-blank, true/false and multiple-choice questions,?sorting, and?data and graph?analysis. This variety of questions is meant to challenge students to think critically and imaginatively about evolution, consolidate their?knowledge?and encourage inquiry-based learning throughout.???Some sections ask students to read an article, watch a video?or analyse a graph and then respond to questions using both the source material and the knowledge they have gained from classroom or textbook learning.?Any external?materials?(videos, websites, articles)?in the worksheet are from exclusively open access resources,?all available through hyperlinks provided.??The worksheets can be completed digitally or printed.?Estimated timings for each section are provided, though you are of course welcome to adjust the timings.?Future Resources and Looking Ahead?If you have any?questions or?suggestions?or feedback on?how we can improve this resource,?or you would like to book a taster lecture or interactive workshop for your school, please?email?us at?anthroschools@ucl.ac.uk.???We will be adjusting this?resource and adding some more, so make sure to check back regularly at? Genetic Diversity and Adaptations in HumansWorksheet detailsIn this first broad topic, students will test their ability to apply their knowledge on genetic diversity and adaptation in exercises and case-studies from a range of interdisciplinary perspectives. The first two sections address natural selection and adaptation in the field of Paleoanthropology, the discipline studying the early development of anatomically modern humans. The last two sections focus on case-studies that show the mechanisms of selection in action, in particular to do with Lactose Intolerance and Sickle Cell diseases.SectionsHuman adaptations and selection pressures in hominid evolutionRecognising selection from fossil evidence and dataNatural selection in lactose intolerance and adaptive phenotypesPhenotypes and environment - Sickle cell case studySuggested Timings20-30mins20-30mins25-35mins25-30minsSyllabus Points3.4 Genetic information, variation and relationships between organisms3.4.4 Genetic diversity and adaptationGenetic diversity as the number of different alleles of genes in a population and its importance for natural selection.?The principles of natural selection and its mechanism?Directional and stabilising selectionNatural selection results in species that are better adapted to their environmentAnatomical, physiological and behavioural adaptations 3.7 Genetics, population, evolution and ecosystems3.7.1 InheritanceThe genotype is the genetic constitution of an organismThe phenotype is the expression of this genetic constitution and its interaction with the environmentThere may be many alleles of a single gene3.7.3 Evolution may lead to speciationVariation in phenotype Definitions and effects on genetic diversityProcess of natural selection leading to evolutionary change1.1 Human adaptations and selection pressures in hominid evolution Learning OutcomesApply evolutionary knowledge to case studies in human evolution students may not be familiar withIdentify and explain examples of human adaptationsCritically think about the emergence of specific patterns and theories of adaptationsAdaptations in hominidsThere are many adaptations that make humans the species they are today. These evolved over?millions of years due to various selection pressures. We can characterise adaptations in behavioural, physiological and behavioural. 4150360144145Hominid = all the species of humans and great apes (both extinct and alive today)00Hominid = all the species of humans and great apes (both extinct and alive today)Here are some examples of other human adaptations:Reduced teeth sizeReduced tailboneBipedalism (walking on two feet)331089074930Bipedalism = the condition of having two feet or using two feet for locomotion00Bipedalism = the condition of having two feet or using two feet for locomotionVaried dietRefined tool useReduced gut sizeSweat glandsSort these adaptations into behavioural, physiological, anatomicalBehaviouralPhysiologicalAnatomicalAll hominids (all the great ape and human species past and present) show a tendency for upright posture, however Homo sapiens are the only living hominid that are habitually bipedal (walk on two legs all the time). Can you think of any reasons why being bipedal would be adaptive and selected for? Theories of bipedalismRead the following article to find out about some current theories of bipedalism. Were your ideas similar?Click here for the articleName two features that are used to identify if a fossil specie was bipedal or notSummarise one of the current main theories for how and why bipedalism evolved1.2 Recognising selection from fossil evidence and dataLearning OutcomesInterpret data relating to the effect of selection in producing change within populationsIdentify types of selection4075430477635Biological anthropologists study human and primate behaviour and biology from an evolutionary perspective.Archaeologists study the material remains of past human lives and activities.00Biological anthropologists study human and primate behaviour and biology from an evolutionary perspective.Archaeologists study the material remains of past human lives and activities.Show understanding that adaptation and selection are major factors in evolution and contribute to the diversity and adaptiveness of living organismsTrends in human brain sizeOne way of understanding how humans evolved is to look at fossil evidence, which acts as a kind of record of the past. Fossils provide a glimpse of what species were alive before the present day and how these changed over long periods of time. Biological anthropologists and archaeologists analyse the fossil record and measure certain features to help piece together evolutionary relationships. Identifying certain trends in how a feature changes can indicate selection, which helps us understand how a species evolved over time.For example, here we will be looking at the feature brain size. The human fossil record contains many human skulls from across the world and of different ages. Brain size is one feature that can be measured and is estimated from the volume of the brain case (where the brain sits in the skull). This is known as the cranial capacity and measured in cubic centimetres.Below is a table containing the measurements of brain sizes for different human fossils.?7924803031490Source 1: Adapted from SEQ Source \* ARABIC 1: Adapted from (mya)0Time (mya)36195022652722370645773021134480527057500What trend do you see in the brain size? Describe thisSelection in human brain sizeWhat kind of selection is occurring here to create this trend? Explain your answerIf you need a reminder about selection, check the info box below!-2698758255000Types of selection:When there is variation in phenotype, selection can cause different changes in phenotype frequency. You should have encountered different types of selection in AQA syllabus point 3.7.3. Here are some graphs to remind you of the different types of selection.47306211708933003269954115622320026343261531651001559842406339Preserves the average phenotypeSelection against extreme phenotypes00Preserves the average phenotypeSelection against extreme phenotypes41241312425000Preserves the extreme phenotypeSelection against the average form00Preserves the extreme phenotypeSelection against the average form21454452408905Selection in the direction of one kind of phenotypeSelection against the other extreme form00Selection in the direction of one kind of phenotypeSelection against the other extreme form170497517145000-19621522606000383857525419400 INCLUDEPICTURE "" \* MERGEFORMATINET INCLUDEPICTURE "" \* MERGEFORMATINET INCLUDEPICTURE "" \* MERGEFORMATINET Why do you think this selection to occurred? Think about why having a big brain would be an advantage.1.3 Natural selection in lactose intolerance and adaptive phenotypesLearning OutcomesExplain why individuals within a population of a species may show a wide range of variation in phenotype Explain how evolutionary change over a long period of time has resulted in a great diversity of species. Identifying the steps of natural selection in the evolution of lactose toleranceRecall definitions and sources of genetic diversity Evolution of lactose intoleranceIn humans our culture and biology have evolved together over time to create the species we are today. One example of this coevolution is between the food we eat and our digestive system; as our diet changed, our digestive system also changed in order to digest different types of food, for instance milk. What enzyme breaks down lactose?Humans haven’t always been able to digest milk. 11,000 years ago, before animal domestication, humans would stop producing lactase once they had been weaned off milk as a child. This would mean humans stopped drinking milk as adult. However, this changed once livestock was domesticated and humans started dairying. Watch this video to see what happened after this. Click here.In order for humans to be able to drink milk into adulthood, the mutant gene would have been selected for and increased in frequency through natural selection. Arrange the following steps to see how lactose tolerance evolved through the process of natural selection.OrderStep in natural selection1In humans the enzyme lactase normally stopped being produced soon after infancy when a child stops drinking milk. Human populations in Northern Europe, East Africa, and the Middle East began to domesticate and rear cattle or camels. The lactose-tolerant populations were able to access the additional energy from sugars in milk. Adding this energy source to their diet meant they were more likely to survive famines.These farming populations with domesticated animals and mutant gene were able to consume and digest dairy into adulthood.A mutation that allowed lactase to continue to be produced into adulthood occurred in some populations. (It is thought a lactose tolerance mutation occurred independently in at least four places around the world). Those who could digest milk better were more likely to survive and reproduce, so these lactose-tolerant populations grew in size.Today, there is variation in the ability to digest milk. Those who are not descendants of these populations did not inherit the ability to digest milk beyond infancy and are lactose-intolerant in adulthood. The genetic variant that allowed milk to be digested into adulthood was passed on between generations and spread rapidly.Genetic DiversityAs you have seen, there is diversity in adaptive phenotypes. Diversity in adaptive phenotypes is achieved through genetic diversity. For example, some people can drink milk and others can’t depending on what gene they have for lactase production. It is this variation in genes that natural selection can work on. But what exactly is genetic diversity?40462206350Need a little help?Definitions for these terms can be found in syllabus point 3.4.4 and 3.7.2, or look at our glossary 00Need a little help?Definitions for these terms can be found in syllabus point 3.4.4 and 3.7.2, or look at our glossary What is the most suitable definition of genetic diversity? The number of different genes in a personThe number of different alleles in a populationThe number of different genes in a population4536440367030Need a reminder on variation? Check out this video here!00Need a reminder on variation? Check out this video here!Genetic diversity can be increased or decreased by different forces as well as natural selection. Let’s investigate the different influences on genetic diversity.Mutation A genetic mutation is a random change to the base sequence of DNA. It can create new alleles which may be harmful or beneficial.MigrationThe movement of individuals into a different population and the subsequent reproduction with individuals of the new population can bring new alleles into the gene pool.MeiosisRandom fertilisation of haploid gametes produces new combinations of allelesGenetic BottleneckA big sudden reduction in population leading to a reduction in the number of different alleles in the gene poolDo these processes increase or decrease genetic diversity? (delete as appropriate)Mutation – increases/decreasesFlow of alleles into the population through migration – increases/decreasesGenetic bottleneck – increases/decreasesMeiosis – increases/decreasesGenetic diversity can affect variation in phenotype, because genes are transcripted and translated into proteins to produce the phenotype. But the phenotype is also influenced by the environment. In the next section we will investigate one interaction between genes and the environment that affects the phenotype produced (see 1.4 Phenotype and Environment – Sickle cell disease case study). 1.4 Phenotype and Environment – Sickle cell disease case studyLearning OutcomesInterpret graphic data on global health Critically apply evolutionary knowledge to the understanding of sickle cell diseaseDemonstrate an understanding of the consequences of a genetic mutation in different environments31089601646555Source 2: Science Photo LibrarySource SEQ Source \* ARABIC 2: Science Photo Library31089606350000Sickle Cell Disease and MalariaIn this worksheet we will be looking at a particular mutation in humans and how it interacts with its environment. Sickle cell disease is a genetic condition caused by the sickle cell gene. The sickle cell?locus?can feature?a mutation in the?Haemoglobin-beta gene (located on chromosome XI). This type of mutation is called a?point mutation: a nucleotide base is inserted/deleted or switched out for another. The shape of the?haemoglobin?protein becomes abnormal leading to changes in the shape of the body’s red blood cells from smooth and round, to?a?“sickle” or crescent shape.??When an individual is homozygous for the sickle cell trait, most of their red blood cells are this sickle shape. This makes it harder for blood to flow through vessels and for oxygen to be transported around the body.??404622058420Check out this video for more information on Sickle Cell anaemia and its relationship with malaria. Click here!00Check out this video for more information on Sickle Cell anaemia and its relationship with malaria. Click here!Look at this graph below:Source SEQ Source \* ARABIC 3: Prevalence of malaria among patients with and without sickle cell disease (SCD), by year of hospital admission, from Komba et al (2009) Malaria as a Cause of Morbidity and Mortality in Children with Homozygous Sickle Cell Disease on the Coast of Kenya. (LINK)Describe and compare the trends in the percentage of people with malaria between individuals with SCD and those without SCD.??Malaria is a?parasitic?organism found in many areas of the world.?Malaria Falciparum, a type of malaria caused by the parasite plasmodium falciparum, accounted for 99.7% of malaria cases in 2018 [WHO 2020]. This parasite enters the human bloodstream through the bite of a malarial vector such as the female?anopheles?mosquito (this is the?most common?form of transmission). After entering the blood, the malarial trophozoites (baby protozoa)?infects red blood cells, changing their properties and causing them to stick together. Those?who are heterozygous for?the sickle cell trait show some protection against malaria. This because the mutation in the?haemoglobin?prevents the malarial trophozoite from changing the properties of the red blood cell, preventing them from sticking together.??029972000730253862705Source 4: ?Source SEQ Source \* ARABIC 4: ?Look at?the map below.?? INCLUDEPICTURE "" \* MERGEFORMATINET Where would you predict incidences of Sickle Cell?Disease?to be highest??Explain why???Based on what you have learnt, reinterpret the graph above, identifying the types of selection involved and when to explain the pattern of percentage of people with malaria in those with SCD.This case study of sickle cell disease shows how?mutations can be beneficial in some contexts,?and environments, and potentially harmful in others.?Anthropologists and social scientists often attempt to study diseases in socio-cultural contexts?rather than seeing inherited disease caused by mutations as binary. Understanding the nature of the mutation and the environment and social context it is in can help create more effective health?interventions.??2 Human Evolution: Speciation and TaxonomyWorksheet detailsThe second broad part of the resource will address speciation and taxonomy from a biological anthropology perspective. The first section will help students think critically about evolution and speciation, with an attention to the notion that each species has evolved for its specific environment, and that evolution doesn’t follow a predictable, straight line. It will also address the different ways human species can be classified. The final section can be considered an extra “challenge” for students interested in human evolution and Palaeoanthropology, looking more closely at the species from our hominin lineage. Sections2.1 Processes of evolution2.2 Classifying human species2.3 Extension Challenge: species in the hominin lineageSuggested Timings2.1 30-40mins2.2 35-45mins2.3 60minsSyllabus Points3.4 Genetic information, variation and relationships between organisms3.4.4 Genetic diversity and adaptationNatural selection results in species that are better adapted to their environment3.4.5 Species and taxonomyDefinition of a species and processes of speciationTaxonomy including the taxa kingdom, phylum, class, order, family, genus, speciesPhylogenetic classificationGenetic sequencing3.7 Genetics, population, evolution and ecosystems3.7.2 Evolution may lead to speciationSpecies exist as one or more populationsConcept of gene pool and allele frequency3.7.3 Evolution may lead to speciationNatural selection as differential survival and reproductionSpeciation through reproductive isolationVariation in phenotype 2.1 Processes of evolutionLearning OutcomesRecall definitions of evolutionary terms and describe the process of speciationAnalyse statements and representations of evolution, natural selection and speciationThis worksheet will investigate the processes of evolution and show how natural selection can lead to new species. To begin with watch this video from Khan Academy for an overview of this topic.Click here!SpeciationFill in the gaps in the following paragraph to test your knowledge on speciation: The evolution of a new species is called _________. A species is a group of organisms which have _______ ________________ and?can interbreed to produce _______ _________. A new species can arise when a small of groups of individuals become ______________ ________ from the original population. This can happen in two ways: __________ speciation is when reproductive isolation is caused by ____________ __________. _________ speciation is isolation caused without a physical barrier, and instead by factors that are ecological, temporal, or behavioural for example.When a population becomes geographically isolated, the new location is likely to have different _____________ conditions, and therefore different _________ _________. Thanks to the mechanisms of _______ _________ the best adapted organisms can survive and _________. Over time enough _______ ___________ will be produced so that if the new population reunited with the original population, individuals would not be able to __________ to produce fertile offspring. This process produces ___ species from ________ species. fertile offspring / reproduce / selection pressures / interbreed / speciation / new / similar characteristics / allopatric / genetic differences / sympatric / natural selection / reproductively isolated / environmental / existing / geographical separation4277360158115Remember!The definition for evolution in the AQA specification is this: change in allele frequencies in a population00Remember!The definition for evolution in the AQA specification is this: change in allele frequencies in a populationWhat does evolution look like?There are many definitions and ways of describing evolution. Often it depends on the scale you are looking at whether that is change at the level of the species, population, of allele frequencies.Let’s look at some common misconceptions about evolution to deepen our understanding. Below are some statements to do with the processes and outcomes of evolution. Are these statements true or false?3985260429260*This sentence means that two completely different species are at the evolutionary stage they ought to be, given their environment. There is no “finish line” for evolution!00*This sentence means that two completely different species are at the evolutionary stage they ought to be, given their environment. There is no “finish line” for evolution!Evolution follows a straight line (is progressive), with more complex?organisms?being the most advanced products of natural selection.???An ant is as evolutionarily advanced as?a?gorilla*.???Humans have evolved from chimpanzees.??Humans’ closest relatives are chimpanzees.??Natural selection would still be able to produce change without variation.??Natural selection acts on phenotypes.??Each?species?has evolved to be?adapted to?their specific environment.??Which one of the following pictures describes?better?the way?evolution?via?natural selection?occurs??Why??-3556001807845A.00A.16256003447415If you are still unsure about these concepts of evolution, check out this helpful video.Click here!00If you are still unsure about these concepts of evolution, check out this helpful video.Click here!252984013335B.00B.268224036893500-172720368300002.2 Classifying Human SpeciesLearning OutcomesRecall the definitions of the different taxa and apply this to human classificationDemonstrate understanding of how analogous and homologous characteristics are used to classify speciesInterpret evolutionary relationships from a phylogenetic treeDemonstrate understanding in how genetic sequence can be used to uncover evolutionary relationshipsTaxonomy and classificationNow that we understand how species are formed, let’s look at how species are classified.Match the classification name to the correct taxa and highlight the binomial name.3215293412981Definitions for these taxa can be found in the glossary if you are stuck00Definitions for these taxa can be found in the glossary if you are stuckKingdomPhylumClassOrderFamilyGenusSpeciesChordata, Animalia, Homo, Hominidae, Mammalia, sapiens, Primates464566066040The five kingdoms are: Prokaryotes, Protoctista, Fungi, Plantae and Animalia00The five kingdoms are: Prokaryotes, Protoctista, Fungi, Plantae and AnimaliaTaxonomy is the theory and practice of classification. Taxonomic classification is what you just completed above. All the identified species in the world have been classified in this way, where groups of organisms are studied to determine what other organisms they are closely related to. The five Kingdoms are a collection of the largest groups, and as you move down the taxa, the groups become smaller, more numerous, and the individuals within them are more closely related.There are many ways to classify species. You could look at specific anatomical features, like whether an organism has wings; for example, grouping organisms that have wings together in one group and those without wings in another group. Using this logic, you could group together butterflies, bats and birds. However, this doesn’t mean these species are closely related to each other evolutionarily. 4409440154940Convergent evolution =organisms that are not closely related and do not share a common ancestor evolve similar characteristics, usually for a similar functionDivergent evolution = organisms from the same common ancestor evolve and accumulate enough differences to form new species00Convergent evolution =organisms that are not closely related and do not share a common ancestor evolve similar characteristics, usually for a similar functionDivergent evolution = organisms from the same common ancestor evolve and accumulate enough differences to form new speciesWings are an example of analogous characteristics: characteristics that serve the same function but have different origins and are the result of convergent evolution. These aren’t that useful when you want to find out if a species is evolutionarily related to each other because they have different origins. Homologous characteristics, on the other hand, are shared characteristics that are derived from a common ancestor, that is, from the same evolutionary origin, regardless of what their function is now. Different functions can arise from divergent selection. Homologous characteristics are more useful if you want to understand the evolutionary relationship between species. This is because if two organisms share homologous characteristics it is likely they are related to each other because they evolved from a common ancestor. See below for an example of analogous and homologous limb structures. INCLUDEPICTURE "" \* MERGEFORMATINET Source SEQ Source \* ARABIC 5: you think of any other kinds of analogous characteristics? Write down two examplesRemember analogous characteristics often have the same function but have different evolutionary origins and therefore will have different structures.PhylogenyHomologous characteristics are used in phylogeny, the study of the evolutionary history of groups of organisms. Phylogenetic trees are used to show evolutionary line of descent and the relationship between species. Take a look at the phylogeny of the humans and our closest relatives. This group of species are collectively called the hominids. 46837601055370Hominids00Hominids43688006985000405638036830Last common ancestor = the most recent species from which all the organisms or species from a particular group have descended from00Last common ancestor = the most recent species from which all the organisms or species from a particular group have descended fromCircle the last common ancestor between humans and chimpanzees. Are gorillas or orangutans more closely related to humans? Why?Are Chimpanzees or Bonobos more closely related to humans (Homo sapiens)? Explain your answer376174025400Want to find out more about how the human genome was sequenced? Check out this video.Click here!00Want to find out more about how the human genome was sequenced? Check out this video.Click here!Genetic sequencingAdvancements in immunology and genome sequencing has helped to clarify evolutionary relationships between organisms. Comparing genetic sequences is another way to understand if organisms are related or not. It is sometimes more accurate than comparing anatomical features (like above) as you can examine the actual DNA sequence of genes to see how they have mutated and changed over time.You can now even buy kits that let you send samples of spit to a lab that sequences your DNA for you to understand your own genetic identity.?Check out the surprising way saliva has brought these six strangers together.?Click here!From an evolutionary perspective, how is?it?possible that six people with different phenotypes share almost the exact same genetic pool???2.3 Extension challenge: Species in the hominin lineageLearning OutcomesPractice reading and digesting a long piece of writing in order to summarise the main pointsDemonstrate the ability to apply knowledge on species to a topic outside the syllabusAnalyse the information gained from the reading from a different perspectiveWho are the hominins?In this section we will be zooming into the human phylogeny and focus on a particular part of human evolution called hominin evolution. The hominins are represented by the orange line on the phylogeny below and are a group containing all the fossils and species from the last common ancestor between humans and the chimpanzees/bonobo lineage all the way up to present day Homo sapiens. Studying this lineage is important if we want to understand our own evolutionary history and what makes us who we are. 4505325608099Hominins00Hominins41859205194300054559201200785Hominids00Hominids446024012382500Although Homo sapiens are the only remaining living hominin, we used to share the planet with many other human species. Over the last century countless archaeological discoveries have uncovered fossils of these now extinct species. Studying these fossils is important to understand the story of our evolution. Human evolutionists look at features, such as brain size, teeth structure, and bone structure, in order to identify the fossil’s species and to see how they relate to other fossils. However, this process can be tricky, and the fossil record is far from complete, so there is a lot of debate in human evolution on the identity of certain fossils, how many hominin species existed and what the exact evolutionary relationship is. We are now going to look at some of the more well-known and understood hominin species. Complete the species profiles below by using information from the following website.Click here!-2032016827500Early homininsSahelanthropus tchadensisEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsOrrorin tugenensisEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsArdipithecus ramidusEstimated age ____________________Date discovered ____________________Location ____________________Main characteristics0-15240000AustralopithsAustralopithecus afarensisEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsAustralopithecus africanusEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsRobust Australopiths/ParanthropusEstimated age ____________________Date discovered ____________________Location ____________________Main characteristics0-10160000The Genus HomoHomo habilisEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsHomo erectusEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsHomo neanderthalisEstimated age ____________________Date discovered ____________________Location ____________________Main characteristicsHomo sapiensEstimated age ____________________Date discovered ____________________Location ____________________Main characteristics3796030-1270For more information on each species follow the links in the glossary!00For more information on each species follow the links in the glossary!Timeline of human evolutionHopefully you are now more familiar with the hominin species!Based on the estimated age of each fossil place these species groups onto the following timeline of human evolutionSahelanthropus / Orrorin / Ardi / Australopithecus / Paranthropus / H. habilis / H. erectus / H. neanderthalis / H. sapiens4064019621500Extra ResourcesExplanation of the process of natural selection - into the history of the theory of evolution - ? Interactive timeline of human evolution - lab where you can interact with human fossils - change in structure, function, or?behaviour?by which a species or individual improves its chance of survival in a specific environment.??Alleles?An allele is a variant form of a gene.??Analogous characteristics?Analogous structures are similar structures that evolved independently in two living organisms to serve the same purpose.??Animalia?That one of the basic groups of living things that comprises either all the animals or all the multicellular animals.?Anopheles?A mosquito of a genus which is particularly common in warmer countries and includes the mosquitoes that transmit the malarial parasite to humans.??Bipedalism?The condition of having two feet or of using only two feet for locomotion.??Chordata?A chordate is an animal that belongs to the phylum Chordata, which is part of the Deuterostomes kingdom (see definition below). The phylum (see definition below) Chordata includes a wide range of organisms, as it is comprised of all vertebrates, which are organisms with a backbone, and many invertebrates; organisms that don't have a backbone.??Class?In biological classification, class (Latin: classis) is a taxonomic rank, as well as a taxonomic unit, a?taxon, in that rank.?Disease Incidence?Incidence refers to the occurrence of new cases of disease or injury in a population over a specified?period of time. Although some epidemiologists use incidence to mean the number of new cases in a community, others use incidence to mean the number of new cases per unit of population.??Evolution?Evolution is change in the heritable characteristics of biological populations over successive generations.??Family?In biology, a family is a taxonomic rank, or a?taxon?at that rank. Each family contains one or more genera (see definition below – Genus).??Gene?A base sequence of DNA that codes for the amino acid sequence of a polypeptide, or a functional RNA.?Genetic Bottleneck?A genetic bottleneck occurs when a population is greatly reduced in size.??Genetic Diversity?The number of different alleles in a population.?Genetic Sequencing?Sequencing DNA means determining the order of the four chemical building blocks - called "bases" - that make up the DNA molecule. The sequence tells scientists the kind of genetic information that is carried in a particular DNA segment.??Genus?Genus, plural genera, biological classification ranking between family and species.?Haemoglobin?Hemoglobin, also spelled haemoglobin, iron-containing protein in the blood of many animals—in the red blood cells (erythrocytes) of vertebrates—that transports oxygen to the tissues.?Heterozygous?A heterozygous individual is a diploid organism with two alleles, each of a?different?type.??Hominin?Any?of the lineages of human beings, including the early human predecessors such as Homo erectus, Homo habilis, Homo neanderthalensis, and Australopithecus species.??Homo sapiens?Homo sapiens, (Latin: “wise man”) the species to which all modern human beings belong. Homo sapiens is one of several species grouped into the genus Homo, but it is the only one that is not extinct.??Hominidae?Hominidae, in zoology, one of the two living families of the ape superfamily?Hominoidea, the other being the?Hylobatidae?(gibbons). Hominidae includes the great apes—that is, the orangutans (genus Pongo), gorillas (Gorilla), and chimpanzees and bonobos (Pan)—as well as human beings (Homo).??Homologous characteristics?Characteristics in different organisms that are similar because they were inherited from a common ancestor that also had that character.??Homozygous?A homozygous individual is a diploid organism with two alleles, each of the?same?type.??Interbreed?(With reference to an animal) breed or cause to breed with another of a different race or species. "wolves and dogs can interbreed".?Kingdom?In biology, kingdom is the second highest taxonomic rank, just below domain.??Lactase?An enzyme which catalyses the hydrolysis of lactose to glucose and galactose.??Lactose intolerance?Lactose intolerance is a common digestive problem where the body is unable to digest lactose, a type of sugar mainly found in milk and dairy products. This is caused by an absence of lactase enzyme in the body.???Locus?The specific location of a gene in a DNA molecule.?Malaria?An intermittent and remittent fever caused by a protozoan parasite which invades the red blood cells and is transmitted by mosquitoes in many tropical and subtropical regions.??Mammalia?A class of vertebrate animals.??Mutation?A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors??Natural Selection?Natural selection is the process through which populations of living organisms adapt and change.?Order?A taxonomic rank used in classifying organisms, generally below the class, and comprised of families sharing a set of similar nature or character.??Parasite?A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.??Phenotype?The term "phenotype" refers to the observable physical properties of an organism; these include the organism's appearance, development, and?behaviour.??Phylogenetic Tree?A?branching?diagram that shows the evolutionary relationships among different biological species based on similarities and differences in their physical or genetic characteristics.PhylogenyPhylogeny, the history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms.??Phylum?A primary category in biological taxonomy especially of animals that ranks above the class and below the kingdom.?Plasmodium?Plasmodium is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of Plasmodium species involve development in a blood-feeding insect host which then injects parasites into a vertebrate host during a blood meal.??Primates?Primate, in zoology, any mammal of the group that includes the lemurs, lorises, tarsiers, monkeys, apes, and humans. In taxonomy, the order Primates is the highest order of mammals. They are placental mammals with good eyesight and flexible hands and feet.??Protozoa?Protozoa are single celled organisms. They come in many different shapes and sizes ranging from an Amoeba which can change its shape to Paramecium with its fixed shape and complex structure.??Sapiens?Homo sapiens is one of several species grouped into the genus Homo, but it is the only one that is not extinct.?Sapiens?is the?present participle of?sapere?or?"to?be wise".??Sickle cell disease/anaemia?Sickle cell?anemia?is an inherited red blood cell disorder in which there aren't enough healthy red blood cells to carry oxygen throughout your body. Normally, the flexible, round red blood cells move easily through blood vessels. In sickle cell?anemia, the red blood?are?shaped like sickles or crescent moons.??Sickle cell trait?Sickle cell trait (SCT) is not a disease, but having it means that a person has inherited the sickle cell gene from one of his or her parents. People with SCT usually do not have any of the symptoms of sickle cell disease (SCD) and live a normal life.??Speciation?The formation of new and distinct species in the course of evolution. Speciation involves the splitting of a single evolutionary lineage into two or more genetically independent lineages.??Species?A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g. Homo sapiens.??Taxon?A group of one or more populations of an organism or organisms that form a?taxanomic?unit of any rank. (plural. Taxa)Taxonomy?The classification of something, especially organisms. A scheme of classification.?Trophozoites?A growing stage in the life cycle of some sporozoan?(type of protozoan)?parasites, when they are absorbing nutrients from the host.??EXTRA SPECIES TERMS:??Ardipithecus ramidus:?see?? afarensis:?see? africanus:?see? erectus:?see? habilis:?see? sapiens:?see? neanderthalensis:?see? Australopiths/Paranthropus:?see? tchadensis:?see??? ................
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