7

In humans, endogenous retroviruses (HERVs) comprise a substantial fraction of the genome, as much as 8%. While many historical viral incorporation events into the primate genome were likely neutral or detrimental (and therefore selected against), some were co-opted and are now functional elements in humans. An example: human syncytin is the envelope gene ...


5

In certain species of parasitic wasp, contained within the wasp genome is the genome for a so-called "polydnavirus". The female wasp somehow creates instances of these polydnaviruses inside its ovaries. When the wasp injects an egg into a member of the host species (likely a caterpillar), several instances of the polydnavirus are also injected along with it....


4

From what I know of ant-Acacia mutualisms, I've never heard of an ant gall in an Acacia. The link in your question also never mentions a gall. You've likely confused either domatia or Beltian bodies as a gall. Both differ greatly from galls in that domatia or Beltian bodies are created by the plant and not by the insect. Domatia are small plant-made ...


4

There are. But they are not that universal. See kappa-particle in Paramecium and Wolbachia in insects. Also, there are different origins of plastids (compare red algae and green algae). Some organisms like Rhopallodia gibba even have plastids of multiple origin. So do most organelles just lose all their DNA? Or is it something that occurs fairly rarely? ...


4

To the exception of many Monocercomonoides (thanks @canadianer for pointing the exception), all eukaryote (incl. animals, plants, fungi and others but excl. bacteria) all have one or more types of endosymbionte (e.g. mitochondria) and cannot function without it. So yes, any eukaryote is an example.


4

Well, holes in rotting trees are not only going to contain rotten tree matter (aka compost :p), but they will also slowly gather fallen leaves, dead insects, dirt, dust and other debris. Even minuscule layers of these substances will essentially form a pile of "soil" with nutrients and minerals needed by the tree. In fact, spruce trees are capable of ...


4

Note This answer makes the presumption that the crotch in the maple's trunk is indeed a breach through its bark, and does reach the inner woody tissues. The heartwood of most trees consists of the dead connective tissues, xylem, which surrounded the cells that once formed the living layer of phloem under the protective bark. That connective tissue itself ...


4

Saccharomyces boulardii. https://en.wikipedia.org/wiki/Saccharomyces_boulardii S. boulardii is a yeast, closely related to S.cerevesiae (if not the same organism). There is a lot of solid data showing use of this fungus as a probiotic can help treat or prevent intestinal infections. Systematic review with meta-analysis: Saccharomyces boulardii in the ...


4

Cleaner wrasse don't only clean within the mouth; although some species may specialize towards mouth-cleaning, it's likely that this behavior began with cleaning elsewhere on the fish's body. Some studies (e.g. Bshary, 2003) suggest a large effect of cleaners on fish populations/diversity, so it seems that there are strong selective pressures for evolving ...


3

Humans (mammals in general) are host to a diversity of commensal microorganisms, including fungi. An individual microbial species is "good for you" when it stays where it is supposed to be and plays nicely with the other microbial species. That same microbial species can become "bad for you" when it is in the wrong place or in the wrong amount. Fungi are ...


3

No, no human (or any other eukaryote lineage) are able to "create bacteria". The story you were told is wrong. However and interestingly, female parasitoid wasps seem to "create viruses" (Herniou et al. 2013). The viruses are part of the wasp genome (lysogenic phase) and detach (lytic phase) in the ovaries only. The viruses, then infect the caterpillar in ...


3

You're thinking too broadly and rigidly about these concepts -- both commensalism and mutualism are types of interspecific interactions. Commensalism is when one species in a given interaction is benefited while the other is neither benefited nor harmed. In a mutualistic interaction, both species benefit from their interaction with each other. Like any ...


3

In the Hoh Rainforest in Olympic National park, there are many "nurse trees" and "nurse logs"; the latter are trees that have fallen and now act as a nutrient source for smaller trees growing on them. Some of the larger trees' roots find their way into the soil, which facilitates their growth, but some smaller trees do not. ...but it's my understanding ...


3

I see that there exists some confusion over the meaning of Symbiosis itself [in reference to the comments and answer(s)]. Your question/ query seeking information about "some type of Symbiosis" that harms one organism without affecting the other in any form is very much legitimate. Amensalism (as responded by Sanjukta) is indeed the answer, but saying that ...


2

Yes, pollinating fig wasps are gall inducing and mutualistic at the same time, and actually essential for the pollination of figs (see e.g Martinson et al., 2015). During the very intricate mutualism, fig wasps deposit eggs in some of the flowers and leave others. The flowers with eggs and later larvae will develop into galls that will produce new wasps but ...


2

Nonpathological bacteria Staphylococcus epidermidis on the human skin are part of normal bacterial flora that help to protect against pathogenic bacteria, such as Staphylococcus aureus. You can get "infected" by Staphylococcus epidermidis the same way as by other skin bacteria and you get a potential benefit from them. http://www.ncbi.nlm.nih.gov/pmc/...


2

Is there a type of symbiosis where an organism is harmed and the other is neither harmed nor helped? No. There seems to be no intimate association (symbiosis) that does not benefit any partner. If not, do you think there's a term for this sort of relation between two organisms? Yes, Amensalism is the biological interaction you are talking about in ...


2

Whoever told you this story is wrong. Bacteria are prokaryotic single celled organisms, humans are eukaroytic multicellular organisms. These are so different, that it is impossible to convert one into the other. When babies are born, their digestive tract is sterile (see reference 1 for details and a huge amount of additional references). However, it is ...


2

TLDR One hypothesis for survival is nitrate respiration. Long Answer Ampount of oxygen available in root nodules is controlled by the host plant by two ways: By presence of leghemoglobin By the diffusion resistance Under anaerobic condition the bacteria survives by making use of denitrification process which could be used to produce ATP under anaerobic ...


2

I don't know about manatees, but sloths have a symbiotic relationship with the moths living in their fur because the moths supplement the sloth's diet with additional nutrients via algae. Sloth moths grow and die in a sloth's fur, decomposing to provide nutrients for the algae. The sloth then eats the algae. What the moth gets out of this is that its larvae ...


2

Any obligate parasite would be an example. An obligate parasite or holoparasite, is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host. If an obligate parasite cannot obtain a host it will fail to reproduce. How about Leishmania?


2

Communication definitely happens, but I don't know of any research into response to disease. One example are molecules known as lectins that help the fungal partner recognize the correct photobiont (algal or cyanobacterial) symbiont. Another example are the physical connections between fungal hyphae and photobiont known as haustoria that appear to help the ...


2

For the scenario you laid out, the short answer is yes. Like @theforestecologist pointed out, interactions can be complex and contingent. Although, in the example you give, it can be easily tested: grow plants with spiders and without, and see if there is a difference in plant fitness. Fitness can be measured directly by looking at, for instance, the ...


1

Mycorrhiza refers to any fungi that forms a symbiotic relationship with a plant. There are many different species, and they are necessary for healthy plant growth in ~70%-80% of vascular plant species with representatives from more than ~90% of plant families. Needless to say, mycorrhiza associations with plants are very common. What you may be thinking of ...


1

Ficus sp. (various sorts of figs); have a close relation with a sort of Wasp's reproduction. Tiny flowers of Ficus are enclosed inside a hollow, pear-shaped concave special-type of inflorescence, also called hypanthodium (term commonly used in flower-stage) or Syconus(term commonly used for fruit stage) when flower stage sometimes c ( from outside it looks ...


1

I'm not sure about all organelles but mitochondria and chloroplasts are commonly used examples of independent devision in eukaryotic cells. They have independent DNA that forms separate mitotic spindles during division. Similar mechanisms likely existed for other organelles originally but the genetic material may have eventually been combined with the ...


1

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0027909 Members of the genus Xenorhabdus are entomopathogenic bacteria that associate with nematodes. The nematode-bacteria pair infects and kills insects, with both partners contributing to insect pathogenesis and the bacteria providing nutrition to the nematode from available insect-...


1

Pasteur and Redi disproved spontaneous generation a century ago. So no, babies are not magically making bacteria in their guts.


1

Every human has it owns unique bacterial biome, and they acquire it the day they are born. Another interesting thing is that the bacteria that each individual acquires gets much of it from there family/parents. An analogy would be portions of bacterial biomes are passed down from generation to generation although each person does generally acquire a unique ...


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