Lecture 18.B

Question 1

theory of evolution?

Answer 1

Species evolve over time

All new species arose through the evolution of an ancestral species (macroevolution)

All living organisms originated from a single common ancestor.

Question 2

Microevolution?

Answer 2

evolutionary change within a species or small group of organisms, especially over a short period.

still same species, just different beak sizes are more pronounced depending on what they eat.

Question 3

Macroevolution

Answer 3

New species, new genus, new family…

Question 4

Fossils

Answer 4

The remains or traces of ancient organisms left in sedimentary rock (most common), or ice, sand or other places.

Question 5

what info do fossils give

Answer 5

Gives you information about the morphology of organisms that lived in the past.
Documents (some of) the biodiversity of the past.
Get some information on where & when they lived
& when there were extinctions or arrival of new species (using the morphological species concept)

Question 6

Limitations of fossil records

Answer 6

Rare that organisms form fossils & mostly of hard-bodied organisms

Info about external but rarely internal form

Evolution can occur without morphological change (ex behavioural); and morphological change can occur without evolution (ex height & diet)

Question 7

pseudofossils?

Answer 7

produced by naturally-occurring geologic processes rather than biologic processes. They can easily be mistaken for real fossils.

Question 8

Homologous features?

Answer 8

organisms with similar structures, but different functions, hypothesized to have a common ancestor

Question 9

Vestigial structures?

Answer 9

structures occasionally become vestigial as species adapt to different modes of life. Ex Kiwi bird doesn’t fly, but still has wings
Structures that have no apparent function and appear to be residual parts from a past ancestor

Question 10

Convergent evolution?

Answer 10

Organisms with separate ancestries adapt in similar ways to comparable environmental demands: have analogous structures
(diff environment, same adaptations)

Question 11

Analogous traits ?

Answer 11

Analogous traits arise when groups independently adapt to similar environments in similar ways

Question 12

divergent evolution?

Answer 12

species with a common ancestor that change to become increasingly different over time

Question 13

divergent evolution vs convergent evolution

Answer 13

convergent evolution involves unrelated species that develop similar characteristics over time, divergent evolution involves species with a common ancestor that change to become increasingly different over time.

Question 14

Convergent evolution, __ structures

Answer 14

Analogous

Question 15

Divergent evolution: Common ancestor, __ structures

Answer 15

homologous

Question 16

concept of Biogeography- geographic distribution of species

Answer 16

different environments, caused different species to evolve from a common ancestor.

Question 17

Using genetics to draw evolutionary trees: limitations

Answer 17

Based on assumption that genes are passed only vertically

• But studies of prokaryotes show on average 80% of the genes had moved b/w species (ie horizontal gene transfer)
• Mammals likely have had genes transferred from prokaryotes

In case of conserved sequences: similar sequences may reflect importance of sequence to function, ie not necessarily a common ancestor, so must look at tons of genes
- Should be looking at non-gene regions too.

Also hybridization of different species can occur

Sometimes molecular evidence supports fossil evidence, sometimes it doesn’t

Question 18

___ can evolve

Answer 18

Populations can evolve: lots of examples. Descent with modification observable. (Species, not individuals, evolve)

Question 19

Darwin based his hypothesis on his study of the __of animals

Answer 19

morphology

Question 20

what were used to create phylogenetic trees

Answer 20

Morphology of animal fossils & to a smaller extent plant fossils, was used to construct evolutionary trees aka phylogenetic trees

Question 21

Genetic analysis has led to?

Answer 21

the modification of evolutionary trees

Question 22

anatomy of a phylogenetic tree

Answer 22

The vertical lines, called branches, represent a lineage, and nodes are where they diverge, representing a speciation event from a common ancestor.

Question 23

selective pressures examples

Answer 23

Predation, competition and disease