The timing of key events in an organism's lifetime, including development, reproduction and death.

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2answers
230 views

What determines the autumn leaf color?

It is autumn out there. Green, brown, red, yellow, and mixed-colored leaves drop from the trees to the ground. What determines the colors of the leaves? Wikipedia tells me Leaf senescence is the ...
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1answer
37 views

Evolutionary support for parenting book “The happiest baby on the block”

The book by Dr Harvey Karp (MD) The Happiest Baby on the Block proposes that the duration of human gestation has evolved as a tradeoff between cranial size and development of the infant. He ...
50
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1answer
5k views

Do bacteria die of old age?

I know that the cells of mammals at least stop dividing when they are old, and then die a programmed cell death. Then other cells have to replace them. But in a bacterial colony, each cell ...
3
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2answers
79 views

In practice, do fishes die from old age?

I was watching sea birds eating fishes and wondered if fishes actually died from old age, or if they are all eaten before this can happen? I reckon some big predator fishes must be able to live long ...
6
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1answer
509 views

Regulation in plants bearing cleistogamous and chasmogamous flowers

In most plants bearing cleistogamous flowers, chasmogamous flowers are also borne by the plants. For example, Viola, Oxalis and Commelina contain both these kinds of flowers.( I am unaware of a ...
3
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1answer
51 views

Are there cannibalistic k-selectors?

My understanding of r- and k-selectors does not go deeper than the wikipedia article. I understand k-selectors to be creatures that put tendentially more effort and energy into rearing their ...
0
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1answer
70 views

Is there already discovered non-carbon form of life?

Rumors going around. Is there research with real form of life based on non-carbon? Or carbon-life is only one what human's history of biology know? Carbon chauvinism
5
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1answer
75 views

Why might you NOT observe a tradeoff between two life-history traits?

I have traditionally thought of and heard about life-history traits (e.g., size at first reproduction, number of offspring, size of offspring, survival, etc., etc.) as drawing from a finite pool of ...
-1
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1answer
88 views

Is the missing “life-ingredient” in today's Earth's existence the reason why we cannot recreate life?

As far as I know there was no report of "life" pop up in a lab or in the nature so far. Everything what we know is only some copy with less-or-more similarity to previous life-form. We certainly can ...
3
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1answer
82 views

Hibernation, Metabolism and Aging

People are beginning to seriously research space travel applications of therapeutic hypothermia, specifically for reducing metabolism and stress on humans traveling to Mars. It seems that as you ...
7
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1answer
325 views

What biological processes cause leaves to change colours in Autumn?

I am curious to learn what are the biological mechanisms that cause leaves of deciduous plants to change colour? What happens to the chlorophyll? What environmental phenomena (temperature/air ...
6
votes
2answers
118 views

Is there theory that connects longevity, time-scale of environmental disturbance, and adaptation?

I'm thinking here about environmental disturbance or like climate change-driven warming. It seems as if there are two macroevolutionary ways to deal with environmental change: 1) Have short ...
4
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2answers
335 views

Is life expectancy linked to intelligence in animals?

For example, animals that live only a few days or a few years are often not very intelligent. In contrast, the most intelligent animals seem to live longer. Is this true? Are there any studies to ...
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1answer
225 views

How do animals/plants change for each season?

The question pretty much sums it up. How do animals/plants change for each: Spring, Summer, Autumn, and Winter? A detailed explanation on distinct behaviour and appearance changes would be nice.
3
votes
0answers
117 views

Is there a standard definition for plant “maturity”?

Is there a species-agnostic metric for identifying plant maturity? There seems to be plenty of literature defining life-history stages for specific crops, but it is not clear if there is a generic ...
4
votes
0answers
85 views

What controls leaf senescence in deciduous tree species, and how can I predict it?

If I want to predict litterfall, what data do I need to collect, and what statistical model might I use? For example, I might use the following coding to record phenological stage every other day, or ...
6
votes
1answer
7k views

Do crocodiles age?

I was watching a talk by Michio Kaku and he mentioned that crocodiles (or possibly alligators, I forget offhand) don't actually age -- they can die, but they essentially go through no aging process ...
5
votes
1answer
199 views

What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?

I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years. Can someone explain in ...
19
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1answer
1k views

Why do ants live so long?

I was surprised to learn that worker ants in some species live many years. I would have expected a lifespan of a few weeks or months (which is apparently the case for many species). What factors ...
15
votes
3answers
505 views

Why do some trees have a life span, while some don't?

I have heard that there is no limit on the growth of trees, but then why do some trees, such as boxelders and poplars, tend to live shorter than redwoods, for example? Some advertisements for improved ...
26
votes
7answers
426 views

Has there been any observation of species adapting the evolution process?

I am very interested in the evolution of the evolution process itself. There are of course a lot of things that influence how evolution will work, but for this question, I am interested in things that ...