Biology 11- Evolution

biological evolution

modern organisms evolved over long periods of time through decent from common ancestors

where was Darwin’s journey too, and what was he sailing on?

the HMS beagle’s five year voyage to South America (and the famous Galapagos Islands)

What specifically did Darwin note about the varying species globally?

Different, but ecologically similar animal species live in similar environments around the globe

What did Darwin find to help prove that species vary over time, and what did that prove specifically?

Fossils, and that some fossils of extinct animals are similar to living species 

In what two ways did an understanding of geology help influence Darwin?

He understood that the earth is constantly changing slowly, over long periods of time, meaning organisms can change too. Knowing the earth was older also made him realize there was TIME for change

 How did Hutton contribute to Darwin’s theory of evolution?

Earth had enough time to evolve because it is very old and geological processes shaped the earths geological features over time (erosion, plate tectonics, volcanos, etc.) which all ti

How did Lyell contribute to Darwin’s theory of evolution?

He came up with uniformitarianism: the geological processes we see today are the ones that shaped the earth, and since the earth/life is changing, organisms will too 

How did Lamarck contribute to Darwin’s theory of evolution?

He said that species aren’t fixed, evolution is explained through natural processes, there is a link between an organism’s environment and it’s body structures 

How did Lamarck propose species changed over time?

By selective use or disuse of organs, organisms acquired or lost certain traits in their lifetimes, these traits could be passed to their offspring and over time this led to change in species. 

 How did Lamarck pave the way for later biologists?

Lamarck was the first to develop a scientific theory of evolution and realize organisms adapt to their environment 

Which of Lamarck’s ideas were true, and which were false?

He was right that species are not fixed, evolution comes through natural processes, and organisms are linked to their environment, but he was wrong when saying acquired traits can be passed to offspring, and that organisms have an inborn drive to be perfect ** 

What caused Thomas Malthus to form his theory about population growth?

He noticed that the human birth rate was higher than death rate 

Which of the following is an idea attributed to Malthus?

If human population grew unchecked, there wouldn’t be enough living space and food for everyone 

Malthus’s idea led Darwin to conclude that..

Many more organism are born than will: survive and reproduce 

How do humans affect artificial selection? What role does nature play?

Nature provides the genetic variation in organisms, and humans choose the trait they like and breed ones with the trait

What is another name for artificial selection?

Selective breeding

What is struggle for existence?

Competition for limited resources (eg. Food, shelter, mates) 

 What is adaptation?

a species becomes better suited for its environment. Any heritable characteristic that increases an organism’ ability to survive and reproduce in its environment in. heritable characteristics are one that are inherited from your parents

What is fitness and how does it relate to an organism’s change of survival and reproduction?

How well an organism can survive and reproduce in its environment

 What is natural selection?

It is the process by which organisms with variations most suited to their environment survive and reproduce more offspring than organisms who are less suited to the environment 

What does natural selection act on?

Inherited traits

When does natural selection occur?

• When more organisms are born than can survive (struggle for existence)

• there is heritable variation in the population (variation and adaptation)

• there is variable fitness among individuals (survival of the fittest)

Where did organisms all descend from?

Ancestors who survived and reproduced

What does common descent suggest?

That all species, living and extinct, are related

What is descent with modification?

The principle that living species descend with changes, from other species over time 

What does the fossil record provide?

Physical evidence of descent with modification over long periods of time (eg. Intermediate fossils) 

Biogeography

The study of where organisms live now and where they and their ancestors lived in the past 

How does geographic distribution of species today relate to their evolutionary history?

Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors

What is a homologous structure?

body parts in different species that have a similar structure and position but may serve different functions. They suggest common ancestry.

What is a homologous protein found in almost all living cells?

Cytochrome C (from our amino acid activity) 

What is an analogous structure?

Structure that performs a similar function, but does NOT share a similar structure (eg. A birds wing and a bees wing) 

What is similar in all organisms genetic code?

DNA and RNA

What are HOX genes?

They help determine the head to tail axis in embryonic development, and there are found in almost all multicellular organism

Why are organisms who are closely related in different habitats?

Natural selection in different yet close places makes different, but closely related species (eg. Finches) 

Why are organisms who are distantiy related in similar habitats?

They have evolved from different species but similar selection pressures (environment) caused them to develop similar adaptations 

what is fitness?

how well an organism can survive and reproduce in its environment

what is adaptation?

any heritable characteristics that increase an organisms’ ability to survive and reproduce in its environment

what are vestigial structures?

inherited from ancestors but have lost much or all of their original function due to different selection pressures acting on the decent

what are biotic factors?

and LIVING part of the environment that an organism may interact with (such as other organisms competing for food, mates, space)

abiotic factors

and NONLIVING part of the environment (light, wind, water. etc)

what are fossils

the preserved remains of a deceased animal

what is biogeography?

the study of where organisms currently live now, as well as where their ancestors lived in the past

What was Charles Darwin’s contribution to science?

He developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through descent from common ancestors

What specifically did Darwin say about the varying of species locally?

different, yet related animal species often occupy different habitats within a local area

3rd pattern of diversity

species vary over time

acquired characteristics

characteristics that an organism acquires during their lives, and CANNOT be passed onto their offspring

natural variation

the difference of traits that naturally occur in a population, eg, height for humans

what did Hutton and Lyell conclude about Earth’s history

they concluded that earth is extremely old and that the processes that changed earth in the past are the same that operate in the present

deep time

the idea that our planet’s history stretches back over a period of time so long that its hard to us to imagine

molecular biology

a tool used to trace the process of evolution. All living organisms from bacteria to plants and animals use identical genetic code

what do similarities in embryonic development do

shows that they come from a similar ancestor. Despite the differences in adult limb bones, each embryo develops in the same order from the same embryonic cells

two biological patterns to support Darwin’s theory of evolution

1. closely related but different (finches)

2. distantly related but similar (mouse+shrew)

what do homologous structures and similarities in embryonic development suggest about the process of evolutionary change?

evolutionary theory explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor

how can molecular biology be used to trace the process of evolution

at a molecular level, the universal genetic code and homologous molecules provide evidence of common descent