125 votes
Accepted

Do bacteria die of old age?

This is a interesting question and for a long time it was thought that they do not age. In the meantime there are some new papers which say that bacteria do indeed age. Aging can be defined as the ...
  • 49.4k
40 votes
Accepted

How long before robin no longer needs the nest on my porch?

According to Cornell's All About Birds website, you will have to wait about a month for the nest to be cleared. The egg incubation period is 12–14 days. Following hatching, the nestlings will remain ...
16 votes
Accepted

Was iron important for the first life on Earth?

Cyanobacteria require iron for photosynthesis and can be found as fossil stromatolites dating back to 3.5 billion years ago. Stromatolites are layered structures made up of cyanobacteria and sediment....
  • 2,723
11 votes

Why do pink rain lilies flower only after rains, and not from being watered?

It looks like sustained or consistent moisture might be (at least part of) the phenological cue for flowering: The wikipedia article mentions that consistent humidity will induce flowering in at ...
  • 5,809
8 votes
Accepted

Do any amphibians start their lives on land?

From wiki: Most amphibians lay their eggs in water and have aquatic larvae that undergo metamorphosis to become terrestrial adults This suggests clearly that not all of them do so. Here are a few ...
  • 67.7k
8 votes

Could we slow down life?

Short answer: Changing something (instead of everything) yes. There are several studies on the impact of environmental factors on life span. Of course it depends from organism to organism. Diet ...
  • 3,028
8 votes
Accepted

What animal has the longest juvenile period?

As you indicate in your question, the average age of sexual maturity is probably the best way to approach this, since immaturity is usually how juveniles are defined. Age of puberty is also different ...
7 votes

What determines the autumn leaf color?

There is no color code for the leafs - the color results from biochemical reactions. Basically there are three colors: Green, yellow and red. Green color is caused by the chlorophyll inside the ...
  • 49.4k
6 votes
Accepted

In practice, do fishes die from old age?

Yes, at least some fishes have intrinsic lifespans and deaths that are related to their own life-history and not to external forces such as predation or disease. Fishes show three types of ...
  • 5,809
6 votes

Why do pink rain lilies flower only after rains, and not from being watered?

It's a nice question, I've tried looking for research papers to no avail. But I will add a few things that I hope will help: Firstly, tap water's composition is quite different from rain water- two ...
  • 213
5 votes
Accepted

Wasn't extinction of dinosaurs necessary?

Basic misunderstand about how one can make sense of nature Nature is not a conscient being (or at least not falsifiable conscient being) trying to optimize the amount of flora or whatever you would ...
  • 67.7k
5 votes

How to gather life-history traits data on bird species?

Have you tried the Ecological Data Wiki? It's an NSF-funded repository of links to ecological databases and datasets: Main page: http://ecologicaldata.org Find data tab, refined to Taxon=Birds, ...
5 votes
Accepted

What fish (and/or shellfish) species with a multi-year life-cycle, besides salmon, die after spawning?

Many species of Eel (order Anguilliformes) have a semelparous life history (most species? all?), i.e. they only reproduce once and then die (as opposed to an iteroparous life history). Many species ...
5 votes
Accepted

How to find the age of a memory stored in the brain?

We are only barely beginning to understand how the brain works, including memory. We do know that it is a very complex thing. There are many different kinds of memory; many different processes are ...
  • 3,190
5 votes

Was iron important for the first life on Earth?

Summary It has been proposed that iron was indeed important for the first life on earth, specifically in combination with sulphur. This is because conditions are thought to have existed in volcanic ...
  • 22.7k
4 votes
Accepted

Any examples of an organism's life cycle where the reproductive stage occur before the 'adult' stage?

There are two important points here: The adult phase is defined as the phase during which reproduction occurs. It is therefore impossible for reproduction not to occur during the adult phase as you ...
  • 67.7k
4 votes

Why are the fertility rates of large predators kept low?

This question can be tackled in several ways, and also seems to contain a couple of misconceptions about ecological processes (e.g. problematic group-selection ideas and how species 'fit' into the ...
3 votes

Why are the fertility rates of large predators kept low?

The way you pose the question, as in what mechanisms limit the fertility of predators, together with your comment about the distinction to the population dynamic aspect, strongly that what you are ...
  • 984
3 votes

Why are the fertility rates of large predators kept low?

In a given area there can be only a limited number of top predators due to resource limitations. Furthermore, as top predators are not hunted upon, a relatively high percentage of offspring will ...
  • 51.5k
3 votes

What determines the autumn leaf color?

What There are two theories according to Jennifer Wells, Leaf Color Change: Competition theory - states that nutrients are redistributed to important parts of the plant. Lack of nutrients in the ...
  • 7,097
3 votes
Accepted

What makes animal to continually reproduce?

Why organisms reproduce If they didn't reproduce, they would die out. More concretely, suppose an animal is born with a mutation that removes the desire to reproduce. That animal will not have any ...
  • 1,564
3 votes

Do Blanding's Turtles die of old age?

It looks like as in fishes, the lack of an intrinsic cause of death in turtles in general is seen: Like in fishes, the reptiles appear to show three types of senescence. The African skink, Mabuya ...
  • 5,809
3 votes

In life history theory, does trade-off between reproduction and growth and maintenance imply longer health span for a sexually inactive organism?

I am not sure if life span could be extended in such circumstances but the probability of survival could probably increase, given the high metabolic costs of growing and raising offspring. I work ...
2 votes

Why is one phase of a plant dominant (Alternation of generation)?

Short answer: Many of the evolutionary developments in plants developed in the sporophyte life stage. Because increased fitness of these increasingly sporophyte-"dominant" plants would result in a ...
2 votes

Real-world examples of Darwinian extinction

Although you don't mention it in your question, I guess you'd like examples of extinction in (more or less) constant environment? Then I guess you'd like cases of extinction due to the introduction of ...
1 vote

Is a microspore diploid?

The spores (microspores or megaspores) in gymnosperms are haploid. The microspores came from the microsporocytes which are diploids cells of the sporophyte, divided via meiosis. So the haploid ...
  • 11
1 vote
Accepted

How have single-celled organisms learned to survive?

Nothing more than physics Simple physics If you drop a rock, the rock will fall to the ground. If there was a table underneath, the rock would stop its fall when reaching the table. Clearly the rock ...
  • 67.7k
1 vote
Accepted

Why would a human female have a sexual display despite male biased operational sex ratio?

Sexual arms race. There is a fine and internally consistent theory that this strategy by females evolved to oppose the strategy of infanticide by males. Males of many species including primates ...
  • 2,926
1 vote

Do any amphibians start their lives on land?

Arguably, since this frog spends the entire larval stage inside a pitcher plant on land, it has started its life cycle on land. A group of zoologists with Conservation International say they found ...
  • 9,364

Only top scored, non community-wiki answers of a minimum length are eligible