Michael Fortescue (2017) presents, besides new linguistic evidence, also several genetic studies, that support a common origin of the included groups, with a suggested homeland in Northeast Asia.[2]
Typology
Fortescue (1998, pp. 60–95) surveys 44 typological markers and argues that a typological profile uniquely identifying the language families proposed to comprise the Uralo-Siberian family can be established. The Uralo-Siberian hypothesis is rooted in the assumption that this distinct typological profile was, rather than an areal profile common to four unrelated language families, the profile of a single language ancestral to all four: Proto-Uralo-Siberian.

Phonology
A single, voiceless series of stop consonants.
Voiced stops such as /d/ occur in the Indo-European, Yeniseian, Turkic, Mongolian, Tungusic, Japonic and Sino-Tibetan languages. They have also later arisen in several branches of Uralic.
Aspirated stops such as /tʰ/ occur in Korean, Nivkh, Na-Dene, Haida, etc.
Ejective stops such as /tʼ/ occur in Na-Dene, Haida, Salishan, Tsimshian, etc.
A series of voiced non-sibilant fricatives, including /ð/, which lack voiceless counterparts such as /θ/.
Original non-sibilant fricatives are absent from most other languages of Eurasia. Voiceless fricatives prevail over voiced ones in most of northern America. Both voiced and voiceless fricatives occur in Nivkh.
Primary palatal or palatalized consonants such as /ɲ ~ nʲ/, /ʎ ~ lʲ/.
The occurrence of a rhotic consonant /r/.
Found in most other language families of northern Eurasia as well; however, widely absent from languages of northern America.
Consonant clusters are absent word-initially and word-finally, but present word-medially.
A feature shared with most 'Altaic' languages. Contrasts with the presence of abundant consonant clusters in Nivkh, as well as in the Indo-European and Salishan languages.
Canonically bisyllabic word roots, with the exception of pronouns.
Contrasts with canonically monosyllabic word roots in Indo-European, Sino-Tibetan, Yeniseian, Na-Dene, Haida, Tsimshian, Wakashan, Salishan, etc. Some secondarily monosyllabic word roots have developed in Aleut and multiple Uralic languages, and they predominate in Itelmen.

Uralo-Siberian is a hypothetical language family consisting of Uralic, Yukaghir, Eskimo–Aleut, possibly Nivkh and formerly Chukotko-Kamchatkan. It was proposed in 1998 by Michael Fortescue, an expert in Eskimo–Aleut and Chukotko-Kamchatkan, in his book Language Relations across Bering Strait. In 2011, Fortescue removed Chukotko-Kamchatkan from the proposal.[1]
Word-initial stress.
Morphology
Exclusively suffixal morphology.
Contrasts particularly with Yeniseian and Na-Dene.
Accusative case, genitive case and at least three local cases.
singular, plural and dual number.
The absence of adjectives and adverbs as morphologically distinct parts of speech.
Evidentiality marking.
Indicative markers based on participles.
Possessive suffixes.
Syntax
The presence of a copula, used as an auxiliary verb.
Negation expressed by an auxiliary verb (known as a negative verb)
Subordinate clauses based on non-finite verb forms.
None of the four families shows all of these 17 features; ranging from 12 reconstructible in Proto-Chukotko-Kamchatkan to 16 in Proto-Uralic. Frequently the modern-day descendant languages have diverged further from this profile — particularly Itelmen, for which Fortescue assumes substrate influence from a language typologically more alike to the non-Uralo-Siberian languages of the region.

Several more widely spread typologically significant features may also instead represent contact influence, according to Fortescue (1998):

Primary uvular consonants are absent from Uralic, but can be found in Chukotko-Kamchatkan and Eskimo-Aleut. They are also present in Yukaghir, though are likely to be of secondary origin there (as also in the Uralic Selkup, as well as a large number of Turkic languages). They are, however, firmly entrenched in the non-Uralo-Siberian languages of northernmost Eurasia, including Yeniseian, Nivkh, Na-Dene, Haida, Salishan, etc. Fortescue suggests that the presence of uvulars in CK and EA may, then, represent an ancient areal innovation acquired from the earlier, "pre-Na-Dene" languages of Beringia.

https://en.wikipedia.org/wiki/Uralo-Siberian_languages