section 4- natural selection and genetic modification

what is evolution?

The slow and continuous change of organisms from one generation to the next.

who came up with the theory of evolution?

Charles Darwin

How do new alleles rise?

due to mutation

Why does a population show genetic variation?

Because of differences in their alleles

What is selection pressure?

The effect of organism chance of surviving and reproducing

What are examples of selection pressure?

• predation and competition for resources such as:

• water

• food

• mates

other factors like:

• disease

• environmental change/impact

Why does a certain species survive over others?

They have better characteristics, that makes them better adapted to the selection pressure in the environment, giving them better chance of survival, meaning they are more likely to breed.

How can a species change over time?

The beneficial characteristics become more common in the population over time

how do bacteria grow resistance to antibiotics?

A resistant bacterium is better able to survive, and then reproduce. This leads to the allele tor antibiotic resistance to being passed on to a lot of offspring’s, so it spreads and becomes more common in a population of bacteria over time.

What happen to outcompeted species?

They to extinct

Why are bacteria a useful way of providing evolution?

Bacteria rapidly reproduce

What’s a fossil?

Any trace of an animal or plant that lived a long time ego

Where are fossils most commonly found?

In rocks, deeper rocks is where older fossils are.

How does arranging fossils in chronological order help?

The gradual change in organisms can be observed

how do fossil fuel prove evolution?

They prove evidence because they show how species have changed and developed over billions of years of years

What do fossils suggest about humans?

That humans and chimpanzees evolved from a common ancestor

what are human being and their ancestors known as?

hominids

Who is Ardi?

A fossil that was found 4.4 million years ago.

What is Ardi structure like?

• her feet suggest she climbed trees

• ape like but tie

• long arms, short legs

• her brain was the same size as a monkey

• structure of her leg suggested she walked upright

Who is lucy and how is she structured?

She was found 3.2 million years ego.

• she had arched feet

• Her brain was slightly larger than Ardi

• walked upright more efficiently than Ardi

Who are the three found fossil fuel ape-humans?

Ardi, lucy and Leakey

Why are stole tools helpful in providing evidence for human evolution?

It showered how the homo species kept evolving due to the stones becoming more complex, showing in their brain must have gotten larger

How can scientists figure out how old a stone tool is?

• Looking for structural features of the tool

• study the rock later, older rocks layers are normally found under younger ones. Tools in deeper layers are usually older

Why my fairing tools not be accurate?

rick layers may move over time

what is classification?

organising living organisms into groups

Why did classification get introduced?

As technology improved, this included things you can see like a microscope, allowing to see cell structure.

what are the five kingdoms?

• animals

• plants

• fungi

• prokaryotes

• protists

what are the kingdom subdivided into?

Phylum, class, order, family, genus and species.