Answer the questions below by writing five to ten sentences for each question. 1

Question

Answer the questions below by writing five to ten sentences for each question.

1. The ancestor of penguins was a bird that could fly. Based on the habitat that penguins are living in today, how would you expect selection to have modified phenotypic traits in the lineage leading to penguins? What are traits evolution may not have been able to change? What are traits that may not have needed to change? Why?

2) In class, we discussed how whales are aquatic, despite having terrestrial ancestors. One evolutionary constraint that they face is having to breathe air. Think of another organism and an example of an evolutionary constraint that limits their adaptation to their habitat. (Choose any habitat except the ocean!). What is the constraint? How does it limit them in that habitat? What is another species that doesn't face that constraint?

3) Environments around the world are changing rapidly due to humans' effects on the planet. What is an example of a way that a species could be evolving in response to human-mediated environmental change?

Explanation / Answer

1 ) Present penguins are indeed evloved from flying birds, but there are some hypothesis that researchers conducted based on Royal Ontario museum and conclude that penguins diverged from the ancestors of petrels & Albtrosses. Some found emperor and king penguins is the oldest living lineage , but the truth is flying birds are the ancestors of present penguins.

Phenotypic change that penguins acquire is definitely a gradual process by natural selection and survival of fittest because it is believed that, earlier birds found a stock of food in the aquatic regions that is not sufficient on land and then they moved towards the marine ecosystem start doing all the activities. Like they have had to jump into the water for foraging which kept going and so their characters such as they lost their wings and acquire Flippers, more feathers, body became streamlined and tappered at both the ends, they got webbed feet for swimming. They also got fat under skin called Blubber which is also present in whales ( adipose tissues). They turned their diet to fishes and crustaceans and got more intelligent as well.

The traits that was not been able to change or not needed to change was I think the penguins beak/bill. Because somehow they have to catch their prey with their beaks as their wings got shorten and also they are able to walk to hold the prey and could get the prey inside their beak which is provided with a small horny spines.

2 ) Well the organisms except aquatic, which face evolutionary constraints are the arthropods, which evolved from small worm like ancestors like spiders, scorpion.

The constraints that the large arthropods ( Branchipods, horse shoe crabs etc.) are facing is molting which is too hard for a large body than small insects. Another constraints are there chitin which are very much adequate in support of small arthropods, but when it comes to large arthropod, then they face problems. Insects doesn't face these problems.

3 ) As we know since the life began the whole environment change is about 1 % only with much divastating and disastrous effects on Earth atmosphere. Over time when modern science became advance we became more powerful to create anything by genetic engineering. There is no doubt that species got extinct due to human activities such as passenger region, dodo, quaga and many more, we can call it as human mediated species extinction. Similarly, we can also say human mediated speciation if the species are being produced by us indirectly. One way of speciation by humans are indeed relocation or invasion of exotic species or by taking indigenous species to abroad, now the resulting species which is called alien species now, has a choice whether to adopt that particular environment or get replaced. Many species get off their existance by this way but some have adopted and evloved accordingly such as myxoma virus introduced to Australia to control rabbit population and entamophanga maimaiga Fungus introduced to USA from Japan.

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