In biology, the scientific name of a species (known as the "binomial name" or just the "binomial" or sometimes even just the "binomen") is written as a pair of words in italics (or underlined, which is the equivalent of italics in handwriting). For example, modern humans belong to the genus Homo and, within this genus, to the species Homo sapiens.
The first word specifies the genus (meaning a group of related species) and has an initial capital, while the second word specifies the species, which doesn't have an initial capital, even if it is derived from the name of a person, e.g. the scientist who discovered the species.
For example, that Wikipedia article says, "[...] the binomial name of the annual phlox (named after botanist Thomas Drummond) is now written as Phlox drummondii." Note that in the phrase "annual phlox", which is not in italics, "phlox" has a lower case initial. So in this case it seems that Wikipedia thinks it is acceptable to write "phlox" in all lower case.
And yet I've often read that a genus name must always start with a capital letter. For example https://en.wiktionary.org/wiki/genus_name says, "genus name (plural genus names)
(taxonomy) The scientific name of a genus, which is always capitalized; the generic name or generic epithet.
Usage notes The scientific name (binomen) of a species is a two-part name and is typeset in italics, the genus name (the first name) has an initial uppercase (capital) letter and the species epithet (or specific epithet) is written with a lowercase (small) letter; for example, the scientific name of the wild Rock Dove is Columba livia.".
First, notice how the dictionary quoted above wrongly has "wild Rock dove". It should be "wild rock dove" of course. Ha ha.
Now, if you will, imagine people somewhere had started to refer to one or more locally found species of the genus Columba as "Columbas"/"columbas". This could happen because calling them "rocks" would be confusing. After all, rocks do sometimes fly, land, and so on. In writing they write them without italics or underlining and sometimes without an initial capital. So my question is: Would the latter be acceptable in formal writing among nonscientists?
To me it seems a bit anomalous for something that is a type of animal to get a capital letter. It's as if biological jargon has spilled into ordinary English, and where it conflicts with the rules of the latter, it just brushes them aside. The italics/underlining rule is rarely followed by nonbiologists, so do we really have to always follow the capitalize all genus names rule? Can't we follow the English rule that says types of animal are not capitalized?