Evolution And Adaptation Flashcards
What are fossils?
Remains or traces of animal or plant life found in rocks; preserved by natural processes over millions of years
Fossils can provide critical information about the history of life on Earth.
What are the three ways of forming fossils?
- Preservation when decay is not possible
- Mineral replacement
- Hardening soft materials
Each method contributes to the different types of fossils found in the geological record.
What conditions allow for the preservation of fossils?
Decomposers cannot act, such as in glaciers and peat bogs
This lack of decomposition facilitates the preservation of organic material.
What is mineral replacement in fossil formation?
Hard parts of organisms are gradually replaced by minerals as they decay slowly, creating a rock-like substance
This process can lead to the formation of detailed fossilized remains.
How can casts or impressions be formed in fossils?
When clay hardens around an organism, the organism decays leaving behind a cast
This process captures the outer shape and details of the organism.
Why is the fossil record considered incomplete?
- Many early forms were soft-bodied and did not leave significant traces
- Geographical activity has caused destruction
These factors limit the number of fossils available for study.
What evidence supports the theory of evolution?
- Fossils
- Antibiotic-resistant bacteria
Each of these provides insight into how species adapt and change over time.
How do bacteria evolve rapidly?
Bacteria reproduce quickly, and mutations occur
This rapid reproduction allows for faster evolutionary changes compared to other organisms.
What happens if bacteria become antibiotic-resistant?
When treated, the resistant bacteria can survive and spread since there is no effective treatment
This poses significant challenges for medical treatment and public health.
What is extinction?
The situation where no animals of a species are left in the world
Extinction can occur rapidly or slowly due to various factors.
What factors can cause rapid extinction?
- Abiotic factors
- Biotic factors
Changes in the environment can lead to rapid declines in species populations.
What are examples of abiotic factors that can lead to extinction?
Volcanic eruptions affecting CO2 levels, blocking light, and causing pH changes in soil
Such environmental changes can severely impact ecosystems.
What is a slow extinction?
Extinction that occurs due to geographical and atmospheric changes over time
This process can be gradual and may take generations to fully impact a species.
What is stabilising selection?
A type of natural selection that favours the average phenotype
It occurs when the environment is stable and does not change significantly.
What is directional selection?
A type of natural selection that favours extreme phenotypes
It typically occurs after an environmental change.
Give an example of stabilising selection.
Examples include:
* Birth weight
* Eggs laid
* Camouflaged fur
These traits tend to be more advantageous in stable environments.
Give an example of directional selection.
Antibiotic resistance
This shows how bacteria evolve in response to antibiotic use.
What is the Linnaean classification system?
A system that categorizes organisms based on structure and characteristics
Developed by Carl Linnaeus.
List the hierarchical levels of the Linnaean classification system.
The levels are:
* Kingdom
* Phylum
* Class
* Order
* Family
* Genus
* Species
This system helps in the identification and classification of organisms.
What is the binomial naming system?
A two-part naming system for species where the first name is the Genus and the second name is the species
This system was also developed by Carl Linnaeus.
What is the three-domain system?
A classification system that places organisms into three domains based on chemical analysis
Developed by Carl Woese.
Name the three domains in the three-domain system.
The domains are:
* Archaea
* Bacteria
* Eukaryota
Archaea includes primitive bacteria known as extremophiles.
What do evolutionary trees represent?
They show how scientists believe organisms are related
The start of the tree indicates a common ancestor, with branches showing evolved species.
What are ecosystems composed of?
Ecosystems are made up of biotic and abiotic factors
Biotic factors include living organisms while abiotic factors include non-living elements.
