Contrasting the divergent views of RambaM/RambaN and Rashba/Rivash on when modern science and treifot contradict. Their views of science, and of the nature of a halacha l'moshe m'sinai, are contrasted.
For the last article, cf. "Scientific Changes And Halacha" by Rabbi Gil Student, at http://www.yasharbooks.com/Open/OpenAccess03.pdf and http://www.aishdas.org/toratemet/science.html. In particular, see the section on treifot, contrasting the "ignore science" approach of Rashba/Rivash, the "nature has changed" approach of Rav Moshe Feinstein and Hazon Ish, and the unique approach of Rambam following Rambam's view of the nature of the Oral Law.
For treifot, see also the Hakdamah (Introduction) to Rabbi Moshe Shmuel Glasner's Dor Revi'i, perush to Mesechet Hullin. For details on Rabbi Glasner, see http://en.wikipedia.org/wiki/Moshe_Shmuel_Glasner and www.dorrevii.org. In particular, at the latter URL (which is the page by David Glasner, Rabbi Glasner's descendant, devoted exclusively to Rabbi Glasner), there is an abridged translation of his Hakdamah.
The Hakdamah deals with the Oral Law in general. Rabbi Glasner's son, Rabbi Akiva Glasner, taught Rabbi Eliezer Berkovits (http://michaelmakovi.blogspot.com/2009/01/rebbe-and-talmid-come-together.html), and unsurprisingly, Rabbis Glasner and Berkovits share a common philosophy of TSBP. In brief, the halakhah used to fluid and dynamic, until the Talmud was sealed (Rabbi Dr. Isidore Epstein seems to agree - http://michaelmakovi.blogspot.com/2009/01/rabbi-dr-isidore-epstein-on-oral-law.html).
Let me quote the relevant section of the Hakdamah here, from the draft unabridged translation of David Glasner (Rabbi Glasner's descendant, author of www.dorrevii.org, and my partner in writing the Wikipedia page):
Let us now return to our main topic, namely that by making a permanent text of the Oral Torah, we also made the principle (Song of Songs Rabbah 1:18) "even if they shall tell you that the right hand is left and the left hand right," which, based on Scripture, applied only to the generation of any particular Sanhedrin that issued a ruling, permanent for all generations. In other words, should a later generation find that the Sages of the Talmud erred, we are obliged to follow the opinion agreed upon by the early authorities whether the ruling was lenient or stringent. For it is better, as the Hinukh wrote, to suffer a mistake in one halakhah than, Heaven forbid, to demolish the entire structure. And even concerning matters that rest upon science or other disciplines, we may not deviate from what was accepted as halakhah in the Mishnah or the Gemara. And this is what the Sages meant by the remark in Hulin 54a, "May we then add to the list of [fatal] defects [tereiphot]? We accept only those enumerated by the Rabbis" The Rambam (hilkhot shehitah 10:12-13) explains this
passage as follows:
And we may not add to these fatal defects at all, for any injury or disease that befalls a domesticated or undomesticated animal or a foul other than those enumerated by the Sages of earlier generations, which
were accepted by Jewish courts, may not be fatal. And even should it become known to us through medical science that an injury or disease not enumerated by the Sages is fatal, and similarly if it should become known to us through the current medical science that one of the injuries or diseases enumerated by the Sages as a fatal defect is not necessarily fatal, we accept only what our Sages enumerated, for it is written (Deuteronomy 17:11) "according to the tenor of the law which they shall teach you" (al pi ha-torah asher yorukha)
Come and see how distant is the view of Maimonides from that of the Rashba in his responsum 98 in which he seeks to deny, on the strength of a tradition from our Sages, the reality that is evident to everyone. But Maimonides held a different view: namely, that since it had been accepted by Jewish courts that these injuries and diseases were fatal defects, and that acceptance had, through the redaction of the Talmud, been preserved for the generations, we accept only what the Sages enumerated, whether it be lenient or stringent. And this must be so because we judge whether a murderer is subject to the death penalty for killing a person with an incurable and fatal defect based on the assessment of the physicians, whether it be lenient or stringent, and, in this assessment, we pay no attention to the tradition of our Sages concerning the fatal defects of an animal.