#kin selection

Behaviour

Behaviour is the way an organism responds to internal or external changes. It can be innate, which means that it is inborn, such as running for shelter when you hear a loud noise, or it can be learnt, such as when a child learns to share their toys. Most behaviours are carried out in response to a stimulus. For example, when we are hungry, we eat. Eating is the response to a stimulus. 

The study of behaviour and its evolutionary component is called ethology. There are 3 scientists accredited with forwarding this field of science. Karl von Frisch, who extensively studied honey bee communication, specifically their “waggle dance” (informally known as bee twerking), Konrad Lorenz, who studied imprinting, and Niko Tinbergen, who is known for studying fixed action patterns.

Fixed Action Pattern

A fixed action pattern is an innate, stereotypical behaviour that must finish once it has begun. Some scientists abbreviate it, however, I will not, for very good reason. Fixed Action Patterns are initiated by an external stimulus called a sign stimulus. When this stimulus is exchanged between members of the same species, they are known as releasers.

Tinbergen studied the stickleback fish. This fish attacks other males who try to invade his territory. The releaser for the attack is the red belly characteristic of males of his species. The stickleback will not attack another male without a red belly, however, will attack inanimate models, as long as the red belly is visible.

Learning

Learning is a complex process, where the responses of an organism are modified due to experience. Lifespan, and brain complexity both impact the ability of an organism to learn.

Habituation

Habituation is one of the most simple forms of learning, where an organism learns to ignore a persistent stimulus. If you tap a dish with a hydra, at first it will shrink and become immobile, however after a while, it will ignore your tapping.

Associative Learning

Associative learning is a type of learning, where one stimulus becomes linked to another. Examples of this are classical conditioning and operant conditioning.

Classical conditioning was discovered by Ivan Pavlov. He trained a dog to associate an unconditioned response with a neutral stimulus. By ringing a bell every time he would feed a dog when he rang the bell, the dog would begin to drool.

Operant conditioning is also known as trial and error learning. It is a process where behaviour is encouraged or discouraged, by providing reinforcement, or punishment on a specific schedule. 

Imprinting

Imprinting occurs during a critical period of a young organisms life. It is irreversible for the length of that period. A good example is how ducklings learn to follow their mothers and copy what their mothers do. This response disappears when the animal is capable on its own.

Konrad Lorenz studied imprinting with geese. Lorenz imprinted baby geese to himself and watched how they followed him everywhere he went.

Social Behaviour

Social behaviour is defined as an interaction between two or more animals, normally of the same species. This field of study was developed in the 1960s, so is very new.

Cooperation

Cooperation allows a group of animals to be more successful at a given activity, like hunting. Wolf packs are extremely successful at hunting prey much larger than themselves for this reason

Agnostic Behaviour

Agnostic behaviour is aggressive behaviour. It involves threats, and actual violence to settle disputes. These disputes are often about access to resources, like food, mates, or shelter.

Symbolic behaviour, like snarling, raising fur, standing on hind legs, and growling may be used in place of violence. An animal gives in by displaying submissive behaviours, such as losing eye contact, leaving the tail between the legs, or walking away.

Dominance Hierarchies

Dominance hierarchies are the pecking order that decides the social position of an animal. The top of the pecking order often has access to the best resources and is often the fittest animal in the group.

Territoriality

An animals territory is what it defends from other members of the community. Animals use agnostic behaviour to defend their territory. 

Altruism

I would give my life for 2 siblings 4 nieces/nephews 8 cousins

I would give my life for 2 dear friends 2 dedicated students

A teacher once told me That being gifted, is Having a gift to give.

The current exchange rate For my life on loan Has a worse going-rate Than was advertised. So I'll have to find alternatives To mort/gage in its stead:

Like words And stories And knowledge

Or a bitter, sardonic poem

I don't give love, that's because An inch of love is an inch of ashes. But if you can afford to wait I'll give you trust instead.

My trust is light and easy to carry, And worth its weight in gold. You can burn it in a pinch If you need an inch of ashes.

What is not to like about cycads? They are beautiful, they are ancient, and they have a bizarre reproductive biology. Well, we can now add kin recognition to that list. That's right, cycads can somehow discern when they are growing next to a relative and when they are growing next to an unrelated individual. What's more, this discovery means that kin selection in plants is not only ancient, it is probably more wide spread than we ever thought. 

Kin selection and cycads starts at the roots. Although it isn't easy to see, competition for root space is critical for most plant species. Roots are how plants obtain water and nutrients so maximizing root growth is of paramount importance for a plant. This often means taking up space before their neighbors can. That is, unless, that neighbor is your sibling. Researchers set about testing this phenomenon in the lab. By using specialized growth chambers, they were able to compare how plants "behaved" when grown next to their siblings vs. unrelated individuals. What they found was quite astounding. 

Cycads growing next to their half siblings allocated significantly less energy to root growth than when they were growing next to unrelated plants. This had implications for their overall size as well. Plants growing next to siblings were significantly smaller at the end of the experiment. This may seem like a disadvantage until you consider it from the perspective of their genes. Half siblings share 50% of their DNA. Since life is all about getting as many copies of your genes into out into the environment as possible, it stands to reason that competing with copies of yourself is often counter productive. That is not the case when no genes are shared. Plants growing next to unrelated individuals responded with increased root mass and thus increased growth. In other words, they were more competitive. 

Examples of kin selection abound in the animal kingdom. The same is not true for plants (click here for another example). What this research does, however, is show us that we probably haven't been looking hard enough. Although extant cycad species are not those that once shared the environment with dinosaurs, the lineage to which they belong is nonetheless quite old. If such cases of kin selection occur in cycads, then it stands to reason that this is an ancient phenomenon. 

Further Reading:

http://bit.ly/2cmxp4i

This is a picture of me and one of my favorite scientists, my older sister Esther! We both like sweet hats, the great outdoors and just hanging out. Growing up with her made my childhood awesome, and our friendship as adults has enriched my life.

Robin Marantz Henig recently explored some of the research into relationships between adult siblings. How are those relationships shaped by our childhoods? How do they influence our health? According to one Swedish study:

... satisfaction with sibling contact in one's 80s was closely correlated with health and positive mood — more so than was satisfaction with friendships or relationships with adult children.

Beer & Bread: It’s a Family Thing, Even for the Yeast

I’m not much interested in the biotechnology implications here. But making beer and bread are among my family’s favorite pastimes, and it’s fascinating that the yeast doing the real work also recognize family bonds.  They’re single-celled microorganisms, but they nonetheless help out kin and exclude outsiders (much more ruthlessly than we could imagine doing).

But, you know, we all say: “Screw…