Evolution and specialisation

Question 1

What are the evidence for evolution?

Answer 1

1. Molecular evidence: evolution means that some changes in DNA and RNA have been done, and thus amino acid sequence of proteins.
2. Selective breeding: if humans could breed plants and animals and see a change and diveristy within the species, natural selection must work the same.

3.Homologus structure: same anatomical strucutres can be found in diverse organisms.
- embryo development
- vestigial structures
-pentadacyl limb.

Question 2

Molecular evidence

Answer 2

Evolution through change in the base seuqence of DNA and RNA, and the amino acids of proteins.

If there are more similaries in the base sequence, the more closely related are the species. The more recently they have had a common ancestor. One looks at DNA if studying two species more closely related; amino acids used if the species are distantly related.

Used to build cladograms.

Question 3

Selective breeding

Answer 3

Artificial selection of plants and animals: leads to changed traits -

increased yield: higher production

behaviour: (pets/transport) friendly?

beauty:

Question 4

Homologous structures

Answer 4

Result from divergent evolution (development of dissimilar traits).

1. Embryo development shows similar patterns across organisms. Vertebrates have tails and terrestial animals have gills.
2. Vestigial structures: a homologus structure that is gradually lost due to not using it anymore. Pelvic bone in whales, appendix in humans.
3. Pentadacyl limbs: five digits, fingers. S

Question 5

Convergent evolution

Answer 5

When similar traits are created due to adaptation to environment rather than common ancestor: developing analogous structures. Similar solutions have evolved several times independently.

Question 6

Speciation

Answer 6

The process in which new species are forming. A specific type of speciation is adaptive radiation.
Opposite is exctinction

Question 7

Adaptive radiation

Answer 7

The geographical separation of a species, which may involve different environments and thus different dominant selection pressure leading to the evolving of two separate species. Two spieces are considered separate when they can no longer breed with offsprings able to reproduce.

EX: chimpanse and bonobos, isolated by Congo river.