Biology - B6 Life on Earth, past, present and future

alleles

genetic variants

Advantageous phenotype

Characteristics that are more suited for the environment, giving an increased chance of survival and reproduction

Evolution

the process of inheriting advantageous characteristics over several generations through natural selection the speed of which is determined by how fast the organism reproduces.

Natural selection

Only organisms which advantageous characteristics survive to breed

Speciation

When evolution occurs to a point where a new species is created (the old and new species couldn’t create fertile offspring together). This can happen due to isolation of two groups

Fossil records

A way of observing evolution over time by arranging them chronologically

Bacteria

This can show evolution as it happens because of the speed of which it reproduces

Selective breeding

This is used to develop new varieties of organisms with desirable characteristics. This can cause reduction in the gene pool

Darwin + Wallace

Based on their observations of isolationism in species especially on islands, they wrote papers on evolution

Darwin’s influence

His theory allowed the creation of a classification system, developments in conservationism and observations on antibiotic resistance in bacteria.

Asexual reproduction

This is a way of producing offspring quickly and with only one parent needed so only occurring in favorable conditions. However this can cause a lack of genetic variation in a species.

Sexual reproduction

This is a way of producing offspring with genetic variation however two parents are necessary and it takes a lot of time and energy.

Classification

The organization of organisms into different groups. systems such as the five kingdom system can be used.

The five kingdom system

This system is a way of classifying organisms. However it is not used as often now as we can use DNA analysis to completely determine the genetic makeup of an organism and even find out how many generations ago it’s linked to another.

Kingdom

The first classification level. This splits organisms into one of five kingdoms: plant, animal etc.

Phylum

The second classification level

Class

The third classification level. Specifying type (i.e. mammal, reptile)

Order

The fourth classification level. determining diet (i.e. carnivora)

Family

The fifth classification level. i.e. Felidae (feline)

Genus

The sixth classification level

Species

The final classification level. Completely specifying the species of the organism

Evolutionary trees

A way of visually laying out the most recent ancestor between a group of organisms.

Biodiversity

This is about the variety of life in a certain aera. It is made up of three main factors, the variation of organisms, genetic diversity, and the variation of ecosystems.

Reducing biodiversity

Increasing population means more resources are needed to support it so more land is needed. Industrialization means we are using more raw resources and making more waste products and pollutants and globalization. This causes damage to the ecosystems, excessive damaging waste and sharing resources causes a lack of variation.

Sustainability

This is using products at a rate less than that of them being recreated without harming the environment

Protecting specific species

This is one way of conservation. This can happen by protecting the natural habitat or taking the organisms to a space away from dangerous activity so things such as breeding programmes can occur.

protecting habitats and ecosystems

This is one way of conservation. It includes protecting specific area to prevent damaging activity. These include nature reserves.

Protecting ecosystems on a global scale

This is one way of conservation. Certain human activities can increase global warming and therefore climate change so by reducing emissions, for example, it can help protect global biodiversity.

Water availability

This is one factor that effects distribution of organisms. This can make the distribution change based on wet or dry seasons or rainfall patterns.

Atmospheric gases

This is one factor that effects the distribution of organisms. This can make the distribution change based on how much pollution is in an area.

Benefit to humans

maintaining biodiversity can protect the future food supply, ensure minimal damage to food chains, provide future medicines and provide industrial materials and food.

Economic issues

Conservation can be incredibly expensive and some developing countries are rich with natural resources which could boost their economy if sold.

Moral issues

A lot of conservation has limited benefit to people. Some people think that it is wrong to prevent developing countries from accessing their natural resources to protect animals. Some acts of conservation include the killing of other species.

Ecological issues

Ecosystems are very complex so the conservation of a specific species could have a knock on effect on the rest of the environment

Political issues

Some conservation efforts require several countries to sign agreements that they may not be willing to do and some conservation schemes can be turned down by local communities.

Environmental change

This can effect food security because it could effect growth patterns of certain crops which could effect the yield or even ability to grow them.

Diet changes

This can effect food security because as people get richer, their diet more consists of different meats which are unsustainable as they are fed crops that could be given to people and graze on land that could be used to grow other crops.

New pests and pathogens

This can effect food security because it can cause a loss of crops or livestock that could create a widespread famine.

sustainability

This can effect food security because damaging methods is likely to negatively effect food production

Cost of agricultural inputs

This can effect food security because agriculture requires several inputs which can be expensive and leave some areas unable to grow crops and therefore not produce enough to feed the area.

Improved nutrition

This improves food security because it ensure livestock are healthy and fertilizers allow crops to have an increased yield.

Chemical control of pests

This improves food security because pesticides can reduce damage done to crops

Hormones

This improves food security because it can increase production of milk , for example, and can control the fruit growth of crops

Selective breeding

This improves food security because It can create plants with high yield or even bacteria resistance.