User:Hunterambrose/Ecological evolutionary developmental biology

Lead[edit]
Ecological evolutionary developmental biology (eco-evo-devo) is a field of biology combining ecology, developmental biology and evolutionary biology. Developmental plasticity, symbiotic relationships, and epigenetics are important concepts in eco-evo-devo and inform investigations into the relationships between the combined fields.

Plasticity-driven adaptation[edit]
Phenotypic or developmental plasticity is the alteration of development through environmental factors. These factors can induce multiple types of variants that increase the fitness of an organism based on the environment they are in. These alterations can be for defense, predation, sex determination, and sexual selection.

Plasticity-driven adaptation acts on evolution in three ways by phenotypic accommodation, genetic accommodation, and genetic assimilation. Phenotypic accommodation is when a organism adjusts its phenotype to better fit its environment without being genetically induced. The trait that is selected by the environment through phenotypic accommodation can then be integrated into the genome. This process is called genetic accommodation. Genetic accommodation allows for traits that were produced by the environment to be passed on, and it gives better responses to environmental changes. Lastly, genetic assimilation is when the induced phenotype is fixed into the genome. The trait is no longer environmentally induced. At this stage plasticity is lost because when the environmental stimulus is lost the phenotype still remains.

In some cases species change their environment to suit them. This phenomenon is called niche construction. These organisms can change unfavorable conditions to fit them. These changes relieve selective pressures to give an advantage they would have otherwise. These advantages could be creating shelters like nests and burrows, modifying the environment physically or chemically, or making shade.

Epigenetic inheritance[edit]
Epigenetic inheritance is the inheritance of epigenetic marks on the DNA induced by environmental factors. These marks alter gene expression patterns, which can be transmitted to the next generation. This means that environmental cues can influence the development of the organism’s offspring. This is similar to the evolution theory of Lamarck. He stated that an organism can pass physical characteristics that the parent organism acquired through use or disuse during its lifetime on to its offspring. This is not entirely true with epigenetic inheritance, but environmental factors like temperature or food availability during the parent’s life can impact the development of the offspring. Many do not consider this phenomenon, and it is quite interesting to consider that things like malnutrition and temperature in one organism can affect the following generations of that organism.

Symbiotic interactions[edit]
Symbiosis describes the relationship between two species living closely together in an environment, and symbiotic interactions are significant influences on eco-evo-devo dynamics. Many symbiotic organisms have co-evolved and, over time, have become reliant on these relationships. The effect on either involved organism may be positive, neutral, or negative, and these effects are used to broadly categorize different types of symbiotic relationships. Symbiotic relationships generally fall into the broad categories of mutualism, commensalism, parasitism/predation, amensalism, or competition, although other categorizations may be used to describe more complex or uncommon interactions. The relationship between clownfish and anemones is one example of a mutualistic symbiosis. Mutualisms are particularly common between ectotherms, making these symbiotic relationships some of the most threatened by climate change.

Climate change[edit]
Climate change may alter the development of organisms. As a type of developmental plasticity, the sex determination of particular animals can be influenced by the temperature of the environment. Some Reptiles and ray-finned fish rely on temperature-dependent sex determination (TSD). The determination takes place during a specific period of the embryonic development. Although the exact mechanisms of this type of sex determination remains unknown for most species, temperature sensitive proteins that determine the sex of alligators have been found. The effects of rising temperatures can already be seen in animals, for example the green sea turtle. Sea turtles produce more females when exposed to higher temperatures. As a result adult green turtle populations are currently 65% female on cooler beaches, but can reach 85% on their warmer nesting beaches. In contrast to the rising female proportion of sea turtles, the fish that use TSD, such as the southern flounder, generally produce more males in response to higher temperatures. Species that are strongly influenced by temperature in their sex determination may be particularly at risk from climate change....... From an evolutionary standpoint, sea turtles' sex chromosomes differ from other species of reptiles, and this difference makes them susceptible to TSD. Researchers believe this phenomenon is worth studying as climate change may one day have an effect on other types of vertebrates.

It is important to note that climate change affects more than just animals when it comes to development. It affects people as well, especially those in developing countries and regions. For example, expecting mothers who are in areas where droughts are more common due to climate change, may suffer from dehydration which can have harmful effects on their child's development. Dehydration can cause amniotic fluid levels to be lower, which directly correlates to the baby's development and can even cause premature birth. Malnutrition in children is a huge problem in developing countries. Rising global temperatures can alter growing seasons for certain food groups, making it hard for children to get the proper nutrients they need for proper development.