Ev ol u t i on a n d A d a p t a t i on

Photo courtesy of p.j.k. @flickr.com) - grante d unde r cre a t ive commons lice nce – a t t ribut ion

Success Criteria

Aim• To understand that animals and plants adapt to their environments.

• To know adaptation leads to evolution.• To know some ways in which plants and animals adapt to extreme

environments.

R eca p

Can you remember what these words mean?

inheritance

evolut ion

adaptat ion

T h e T h eor y of Ev ol u t i on

Evolution describes the changes that happen in the same species, living in the same locat ion, over a long t ime.

Evolution does not describe people changing their bodies by exercise or dyeing their hair. Evolution happens over a much longer time and can only happen between parents and offspring through inheritance.

inheritance adaptat ion

Ev ol u t i on

inheritance adaptat ion

A species is a group of animals or plants that are very similar. Members of a species share the same characterist ics. Humans, lions, sunflowers and cats are all names of a species.

Charles Darwin was a naturalist who lived from 1809-1882 and he is famous for travelling the world, investigating what makes animals and plants different and introducing the theory of evolution.

Ev ol u t i on

Charles Darwin realised that all the living things in a particular species are sl ight ly different , just like we are all unique.

Ev ol u t i on

Life is often very hard for plants and animals and some will die before they get a chance to reproduce. Therefore, offspring who inherit the best characteristics for survival are more likely to reproduce and pass their characteristics on to their offspring.

A peahen picks the peacock with the brightest and biggest tail feathers to mate with. Peacocks have evolved accordingly and it is rare to see one without big and bright tail feathers.Why do you think that is?

Photo courtesy of Jäge r & Sammle r @flickr.com) - grante d unde r cre a t ive commons lice nce – a t t ribut ion

T h e G a l a p a g os F i n ch es

The Galapagos finch parents reproduce and create offspring.

T h e G a l a p a g os F i n ch es

The Galapagos finch offspring are all slightly different and unique.

T h e G a l a p a g os F i n ch es

When bad weather affected plant growth and there were fewer seeds to eat, the offspring had to eat larger seeds that would not normally be part of their diet in order to survive.

T h e G a l a p a g os F i n ch es

Only the offspring with large beaks could break open and eat the larger seeds. Therefore, these offspring survived and the other, smaller beaked offspring died.

T h e G a l a p a g os F i n ch esThe Galapagos finches with large beaks reproduced and had offspring. More of these offspring inherited large beaks and so Galapagos finch species started to evolve to have longer beaks. This is an example of how animals and plants adapt to their changing environment. This process of adaptation is natural select ion.

A ct i v i t yWe’ve heard of two examples of how animals have evolvedthrough natural select ion. Sometimes it’s finding food that’s difficult, sometimes it’s finding a mate, sometimes it’s staying warm (or cold) and sometimes it’s not getting eaten that causes adaptat ion.

Now we are going to compare how plants and animals from extreme environments have adapted to avoid dying out.