Unit 4 : Vertebrate and Mammalian Evolution

Question 1

Compare microevolution and macroevolution, and illustrate their similarities and differences

Answer 1

• Microevolution: Refers to how populations change under the influence of natural selection and other evolutionary forces
• Macroevolution : Refers to how new species and higher taxa are created

Question 2

Outline how species are defined by biologists and how they originate from prior species

Answer 2

• Species are defined as the most inclusive group of organims that can interbreed and produce viable and fertile offspring. They are also larger than a population and also differ because they cannot breed across the lines that divide on species from another

Question 3

Define Cladogenesis (divergent evolution )

Answer 3

• It is the most widely recorded pattern of speciation, in this process different populations of a species evolve in sperate directions becoming increasingly different to a point at which they are transformed into separate species whos members can no longer interbreed .

Question 4

Define Adaptive radiation

Answer 4

• Form of cladogenesis that occurs on a massive scale, in this process hundreds and even thousand of new species divergent from a common ancestor and fill an extensive array of separate niches.

Question 5

Define Anagensis

Answer 5

• in this instance all the populations within a species remain subject to the same evolutionary pressure and maintain genetic compatibility through mating across group boundaries.

Question 6

Define Convergence

Answer 6

• it involves parallel trends in the biological histories of unrelated species, if life forms with different ancestries come to occupy similar niches , they evolve similar characteristics in response. E.g. fish and aquatic mammals, dolphins have developed similar body forms and appendages for swimming

Question 7

Describe how animals are classified and explain how humans fit into these classifications

Answer 7

Animals are put into a lot of different taxonomic groups to classify them and humans fit into a lot of them as well, for instance , the Chordata because we also have spinal cords , the genus homo because we have a large brain and adapt through cultural practices , species sapiens because we have a large brain with a small face

Question 8

Explain why evolutionary relationships are the basis for all scientific biological classification

Answer 8

• This is important because the shared evolutionary history is used to assign names and group organisms , known as cladistics.

Question 9

Explain what a fossil is and discuss how different kinds of fossils are formed

Answer 9

• it is preserved remains of ancient life and they are formed by burying them in sediments