I saw Rabbi Pfeffer’s excellent article on http://dinonline.org/2010/12/30/vaeira-changing-halachah-in-a-changing-world/
Has any research been done to investigate whether nature has really changed eg are there intact bodies of people or animals that are at least 1600 years old?
If there are old corpses (skeletons wouldn’t show enough) do they bear out what it says in bechoros 44a that describe 2 channels in the male sex organ; one for urine and one for semen?
Tosfos chullin 47a describes a little rose lobe that the Talmudic sages said was only in some animals, but is now in all animals.
Nature has changed. The Chazon Ish already writes that there are no two channels now days but only one. (The Gemorah Bechoros is 44b)
Tosefos Avodah Zorah 24 ד”ה פרה, Ramo E:H 156:4, Magen Avrohom O:CH 173:1 & Mishnah Berurah 3 Teshuvas Rabi Akivah Eiger 128, Teshuvas Avney Nezer 238. Chazon Ish E:H 12:7