Human evolution Session 25 Flashcards
what is a traditional fossil ?
- It is a fossil that has characteristics of two different groups
What is the study of Biogeography refered to ?
- The study of the distribution of plants and animals in different places
What are classified as Anatomical evidence ?
- If there is the presence of Homologous structures , vestigial structures , and similar embryological development.
What are homologous structures ?
- They are structures that are anatomically similar because they are inherited from a common ancestors
What are Analogous structures ?
- They are structures that serve the same function but are not contracted similarly nor do they share a common ancestry
What are some examples of vertebrate forelimbs containing the same set of bones organized in similar ways , but have different functions ?
- Birds and bats using them for flight
- Whales and seals using them for swimming
- horses using them for running
What are vestigial structures ?
- They are structures that are fully developed in one organism but a re reduced and may have no function in others
For example ; humans have a tailbone but no tail
Since vertebrates have similar embryological development , what are some things that all vertebrates have during development but may develop into different things ? State one example as well
- A tail and paired pharyngeal pouches
- In fish and amphibian larvae , the pouches develop into functioning gills
- In humans the pouches become cavity of the middle ear , auditory tube , tonsils , thymus and parathyroid glands
What is the correct order of evolution and classification of humans ?
- Domain Eukarya : membrane bound nucleus
- Kingdom Animalia : multicellular , motile and heterotrophic
- Phylum Chordata : dorsal tubular nerve cord , notochord , pharyngeal pouches
- Class Mamalia : Vertebrates with hair , mammary glands
- Order primates : Well developed brain , adapted to live in trees
- Family Hominidae : Adapted to upright stance and bipedal locomotion
- Genus Homo : Most developed brain , made and used tools
- Species Homo sapiens : Modern humans
According to rRNA sequence , what are the three domains of life, characterize each one ?
- Bacteria : Cells do not contain a nucleus
- Archaea : cells do not contain a nucleus , they have a different cell wall from bacteria
- Eukarya : cells do contain a nucleus
What are the two different groups of primates and list examples for each group ?
- Prosimians : lemurs, tarsiers and lorises
- Anthropoids : monkeys , apes and humans
What are some features of the primate ?
- Mobile limbs
- Grasping hands
- Flattened face
- binocular vision
- large brain
- reduced rate of reproduction
What is known as the closest cousin to humans?
- Chimpanzee
what are classified under the Hominid?
- Big apes(gorillas and orangutans) , chimpanzees , humans and the closest extinct relatives of humans
What are classified under Hominine ?
- Only the gorillas , chimpanzees , humans and their closest extinct relatives
What are classified under Hominin ?
- All members of the genus Homo and their extinct close relatives
How big is a chimpanzees brain in comparison to a humans?
- Chimpanzees have a brain size about a third that of humans
What are some unique hominid anatomical features ?
- Bipedal posture ( walking on two feet ) , the shape of the face and brain size
When was the fossil Sahelanthropus tchandesis dated and where was it found ?
- 7 MYA , in chad , in central africa (2001)
When was the fossil orrorin tugenensis dated and where was it found ?
- 6 MYA and Eastern Africa
What were the two different species of ardipithecines found and when were they dated to be ?
- Ardipithecus kadabba dated 5.6 MYA
- Ardipithecus ramidus dated 4.4 MYA
