macroevolution

Question 1

What is the definition of macoevolution?

Answer 1

large scale evolutionary changes that create the formation of new species (speciation) and the formation of new species ranks (“taxa”)

-all evidence of change/evolution are used to help infee or under the relationship between animals.

Question 2

What are the two explanations that explain the patterns of evolution? (Name) What are they relatvent to?

Answer 2

1) theory of gradualism
2) theory of punctuated equilibrium

all in reference to pace, how long or how fast can things evolve?

both explanations of the patterns of evolution are accepted, and have a significant impact on evolution.

overview/overlook:
environmental changes are slow = evolution will be gradual

environmental changes are rapid = rapid evolution.

Question 3

What is the theory of gradualism? Give me an example. What evidence do we have?

Answer 3

large evolutionary changes in species happen because of the accumulation of small and ongoing changes (a process)

-organisms become gradually more distinctive.

long periods of time, small changes accumulation = drastically different organisms compared to the original.

due to this theory, there are fossils of organisms in its transitional form. (transitional fossils)

red bird turns red orange, orange, and then yellow.

Question 4

What is the theory of punctuated equilibrium? What are the 4 main points + an example/explanation?

Answer 4

most evolutionary changes happen because of relatively short/rapid spurts of change, which is then followed by long periods of no change.

–> Most common in NEW environments or environments that are rapidily changing.

1) new species evolve rapidly in evolutionary time (rapid)

2) ability to create different species within smaller more isolated population, due to punctuated equilibrium meaning that changes happen in a breif amount of time, this rapid chance most often happens in smaller, more isolated populations. (WHICH LEADS TO.. (3) )

3) fewer transitional fossils.

4) after the burst of evolution, additional changes are very very slow, (little to not change).

i.e. a red bird rapidly changes into a yellow one.

Question 5

How does mass extinction lead to diversification? (What causses mass extinction? What causes diversification?)

Answer 5

mass extinction = empty ecological niches = organism’s are able to exploit more resources = adaptations/changes developing overtime due to the exposure of new resources/ a new environment.

Question 6

Why are dinosaurs important to explaining diversification and mass extinction?

Answer 6

dinosaurs were dominate vertebrates and carnivorous (ate most of the resources)

• became abruptly extinct after an astroid , that released a lot of energy (that killed many), also astroid smoke and dust, most likes blocked the sunlight.

Question 7

What is synapomorphy?

Answer 7

A derived (obtained) trait that is shared between 2 or more species.

Question 8

What is a Tiktaalik?

Answer 8

A transition form of a speicies that has features of both fish and four-limbed land vertebrates.
–> Bridiges the gap betweem organisms between land and water.

Question 9

What features do tiktaaliks have that make them significant? list 3

Answer 9

They have the features of both land and aquatic animals have (either a cross between the two, or just the same function of a feature that appears different for land animals and aquatic animals)

–> They have both fins and scales, and the fins have close resemblance to the bones of a 4 limb land vertebrate, it has the bones/structure of a arm.
–> Neck and wrist bones

–> Tiktaaliks have a flattened head with eyes on top, which showcases the cross between a conicol head (a head that is mostly seen in aquatic animals) and a flat head (seen mostly in land animals)

–> Has both gills and lungs.